https://github.com/fancymax/leetcode_swift

Learning Swift
https://github.com/fancymax/leetcode_swift

leetcode swift

Last synced: 3 months ago
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Learning Swift

• Host: GitHub
• URL: https://github.com/fancymax/leetcode_swift
• Owner: fancymax
• Created: 2016-11-24T07:29:41.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2018-07-23T13:32:17.000Z (almost 7 years ago)
• Last Synced: 2025-03-21T00:33:03.670Z (3 months ago)
• Topics: leetcode, swift
• Language: C++
• Homepage:
• Size: 10.5 MB
• Stars: 34
• Watchers: 6
• Forks: 14
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# :pencil2: Leetcode Solutions with Swift,Cpp

Update time:  2018-07-23 21:32:04

Auto created by [leetcode_generate](https://github.com/bonfy/leetcode)

I have solved **92   /   819** problems

while there are **139** problems still locked.

If you want to use this tool please follow this [Usage Guide](https://github.com/bonfy/leetcode/blob/master/README_leetcode_generate.md)

If you have any question, please give me an [issue](https://github.com/fancymax/Leetcode_Swift/issues).

If you are loving solving problems in leetcode, please contact me to enjoy it together!

(Notes: :lock: means you need to buy a book from Leetcode to unlock the problem)

| # | Title | Source Code | Article | Difficulty |

|:---:|:---:|:---:|:---:|:---:|

|1|[two-sum](https://leetcode.com/problems/two-sum)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/001-two-sum/two-sum.cpp) [Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/001-two-sum/two-sum.swift)|[:memo:](https://leetcode.com/articles/two-sum/)|Easy|

|2|[add-two-numbers](https://leetcode.com/problems/add-two-numbers)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/002-add-two-numbers/add-two-numbers.swift) [Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/002-add-two-numbers/add-two-numbers.cpp)|[:memo:](https://leetcode.com/articles/add-two-numbers/)|Medium|

|3|[longest-substring-without-repeating-characters](https://leetcode.com/problems/longest-substring-without-repeating-characters)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/003-longest-substring-without-repeating-characters/longest-substring-without-repeating-characters.swift) [Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/003-longest-substring-without-repeating-characters/longest-substring-without-repeating-characters.cpp)|[:memo:](https://leetcode.com/articles/longest-substring-without-repeating-characters/)|Medium|

|4|[median-of-two-sorted-arrays](https://leetcode.com/problems/median-of-two-sorted-arrays)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/004-median-of-two-sorted-arrays/median-of-two-sorted-arrays.swift) [Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/004-median-of-two-sorted-arrays/median-of-two-sorted-arrays.cpp)|[:memo:](https://leetcode.com/articles/median-of-two-sorted-arrays/)|Hard|

|5|[longest-palindromic-substring](https://leetcode.com/problems/longest-palindromic-substring)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/005-longest-palindromic-substring/longest-palindromic-substring.cpp)|[:memo:](https://leetcode.com/articles/longest-palindromic-substring/)|Medium|

|6|[zigzag-conversion](https://leetcode.com/problems/zigzag-conversion)||[:memo:](https://leetcode.com/articles/zigzag-conversion/)|Medium|

|7|[reverse-integer](https://leetcode.com/problems/reverse-integer)||[:memo:](https://leetcode.com/articles/reverse-integer/)|Easy|

|8|[string-to-integer-atoi](https://leetcode.com/problems/string-to-integer-atoi)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/008-string-to-integer-atoi/string-to-integer-atoi.cpp)||Medium|

|9|[palindrome-number](https://leetcode.com/problems/palindrome-number)||[:memo:](https://leetcode.com/articles/palindrome-number/)|Easy|

|10|[regular-expression-matching](https://leetcode.com/problems/regular-expression-matching)||[:memo:](https://leetcode.com/articles/regular-expression-matching/)|Hard|

|11|[container-with-most-water](https://leetcode.com/problems/container-with-most-water)||[:memo:](https://leetcode.com/articles/container-with-most-water/)|Medium|

|12|[integer-to-roman](https://leetcode.com/problems/integer-to-roman)|||Medium|

|13|[roman-to-integer](https://leetcode.com/problems/roman-to-integer)|||Easy|

|14|[longest-common-prefix](https://leetcode.com/problems/longest-common-prefix)||[:memo:](https://leetcode.com/articles/longest-common-prefix/)|Easy|

|15|[3sum](https://leetcode.com/problems/3sum)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/015-3sum/3sum.cpp) [Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/015-3sum/3sum.swift)||Medium|

|16|[3sum-closest](https://leetcode.com/problems/3sum-closest)|||Medium|

|17|[letter-combinations-of-a-phone-number](https://leetcode.com/problems/letter-combinations-of-a-phone-number)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/017-letter-combinations-of-a-phone-number/letter-combinations-of-a-phone-number.cpp)||Medium|

|18|[4sum](https://leetcode.com/problems/4sum)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/018-4sum/4sum.swift)||Medium|

|19|[remove-nth-node-from-end-of-list](https://leetcode.com/problems/remove-nth-node-from-end-of-list)||[:memo:](https://leetcode.com/articles/remove-nth-node-from-end-of-list/)|Medium|

|20|[valid-parentheses](https://leetcode.com/problems/valid-parentheses)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/020-valid-parentheses/valid-parentheses.cpp)||Easy|

|21|[merge-two-sorted-lists](https://leetcode.com/problems/merge-two-sorted-lists)||[:memo:](https://leetcode.com/articles/merged-two-sorted-lists/)|Easy|

|22|[generate-parentheses](https://leetcode.com/problems/generate-parentheses)||[:memo:](https://leetcode.com/articles/generate-parentheses/)|Medium|

|23|[merge-k-sorted-lists](https://leetcode.com/problems/merge-k-sorted-lists)||[:memo:](https://leetcode.com/articles/merge-k-sorted-list/)|Hard|

|24|[swap-nodes-in-pairs](https://leetcode.com/problems/swap-nodes-in-pairs)|||Medium|

|25|[reverse-nodes-in-k-group](https://leetcode.com/problems/reverse-nodes-in-k-group)|||Hard|

|26|[remove-duplicates-from-sorted-array](https://leetcode.com/problems/remove-duplicates-from-sorted-array)||[:memo:](https://leetcode.com/articles/remove-duplicates-from-sorted-array/)|Easy|

|27|[remove-element](https://leetcode.com/problems/remove-element)||[:memo:](https://leetcode.com/articles/remove-element/)|Easy|

|28|[implement-strstr](https://leetcode.com/problems/implement-strstr)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/028-implement-strstr/implement-strstr.swift)||Easy|

|29|[divide-two-integers](https://leetcode.com/problems/divide-two-integers)|||Medium|

|30|[substring-with-concatenation-of-all-words](https://leetcode.com/problems/substring-with-concatenation-of-all-words)|||Hard|

|31|[next-permutation](https://leetcode.com/problems/next-permutation)||[:memo:](https://leetcode.com/articles/next-permutation/)|Medium|

|32|[longest-valid-parentheses](https://leetcode.com/problems/longest-valid-parentheses)||[:memo:](https://leetcode.com/articles/longest-valid-parentheses/)|Hard|

|33|[search-in-rotated-sorted-array](https://leetcode.com/problems/search-in-rotated-sorted-array)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/033-search-in-rotated-sorted-array/search-in-rotated-sorted-array.cpp)||Medium|

|34|[find-first-and-last-position-of-element-in-sorted-array](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/034-find-first-and-last-position-of-element-in-sorted-array/find-first-and-last-position-of-element-in-sorted-array.cpp)|[:memo:](https://leetcode.com/articles/find-first-and-last-position-element-sorted-array/)|Medium|

|35|[search-insert-position](https://leetcode.com/problems/search-insert-position)|||Easy|

|36|[valid-sudoku](https://leetcode.com/problems/valid-sudoku)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/036-valid-sudoku/valid-sudoku.cpp)||Medium|

|37|[sudoku-solver](https://leetcode.com/problems/sudoku-solver)|||Hard|

|38|[count-and-say](https://leetcode.com/problems/count-and-say)|||Easy|

|39|[combination-sum](https://leetcode.com/problems/combination-sum)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/039-combination-sum/combination-sum.cpp)||Medium|

|40|[combination-sum-ii](https://leetcode.com/problems/combination-sum-ii)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/040-combination-sum-ii/combination-sum-ii.cpp)||Medium|

|41|[first-missing-positive](https://leetcode.com/problems/first-missing-positive)|||Hard|

|42|[trapping-rain-water](https://leetcode.com/problems/trapping-rain-water)||[:memo:](https://leetcode.com/articles/trapping-rain-water/)|Hard|

|43|[multiply-strings](https://leetcode.com/problems/multiply-strings)|||Medium|

|44|[wildcard-matching](https://leetcode.com/problems/wildcard-matching)|||Hard|

|45|[jump-game-ii](https://leetcode.com/problems/jump-game-ii)|||Hard|

|46|[permutations](https://leetcode.com/problems/permutations)|||Medium|

|47|[permutations-ii](https://leetcode.com/problems/permutations-ii)|||Medium|

|48|[rotate-image](https://leetcode.com/problems/rotate-image)|||Medium|

|49|[group-anagrams](https://leetcode.com/problems/group-anagrams)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/049-group-anagrams/group-anagrams.swift)|[:memo:](https://leetcode.com/articles/group-anagrams/)|Medium|

|50|[powx-n](https://leetcode.com/problems/powx-n)||[:memo:](https://leetcode.com/articles/powx-n/)|Medium|

|51|[n-queens](https://leetcode.com/problems/n-queens)|||Hard|

|52|[n-queens-ii](https://leetcode.com/problems/n-queens-ii)|||Hard|

|53|[maximum-subarray](https://leetcode.com/problems/maximum-subarray)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/053-maximum-subarray/maximum-subarray.cpp)||Easy|

|54|[spiral-matrix](https://leetcode.com/problems/spiral-matrix)||[:memo:](https://leetcode.com/articles/spiral-matrix/)|Medium|

|55|[jump-game](https://leetcode.com/problems/jump-game)||[:memo:](https://leetcode.com/articles/jump-game/)|Medium|

|56|[merge-intervals](https://leetcode.com/problems/merge-intervals)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/056-merge-intervals/merge-intervals.cpp)|[:memo:](https://leetcode.com/articles/merge-intervals/)|Medium|

|57|[insert-interval](https://leetcode.com/problems/insert-interval)|||Hard|

|58|[length-of-last-word](https://leetcode.com/problems/length-of-last-word)|||Easy|

|59|[spiral-matrix-ii](https://leetcode.com/problems/spiral-matrix-ii)|||Medium|

|60|[permutation-sequence](https://leetcode.com/problems/permutation-sequence)|||Medium|

|61|[rotate-list](https://leetcode.com/problems/rotate-list)|||Medium|

|62|[unique-paths](https://leetcode.com/problems/unique-paths)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/062-unique-paths/unique-paths.cpp)||Medium|

|63|[unique-paths-ii](https://leetcode.com/problems/unique-paths-ii)|||Medium|

|64|[minimum-path-sum](https://leetcode.com/problems/minimum-path-sum)||[:memo:](https://leetcode.com/articles/minimum-path-sum/)|Medium|

|65|[valid-number](https://leetcode.com/problems/valid-number)|||Hard|

|66|[plus-one](https://leetcode.com/problems/plus-one)|||Easy|

|67|[add-binary](https://leetcode.com/problems/add-binary)|||Easy|

|68|[text-justification](https://leetcode.com/problems/text-justification)|||Hard|

|69|[sqrtx](https://leetcode.com/problems/sqrtx)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/069-sqrtx/sqrtx.cpp)||Easy|

|70|[climbing-stairs](https://leetcode.com/problems/climbing-stairs)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/070-climbing-stairs/climbing-stairs.cpp)|[:memo:](https://leetcode.com/articles/climbing-stairs/)|Easy|

|71|[simplify-path](https://leetcode.com/problems/simplify-path)|||Medium|

|72|[edit-distance](https://leetcode.com/problems/edit-distance)|||Hard|

|73|[set-matrix-zeroes](https://leetcode.com/problems/set-matrix-zeroes)|||Medium|

|74|[search-a-2d-matrix](https://leetcode.com/problems/search-a-2d-matrix)|||Medium|

|75|[sort-colors](https://leetcode.com/problems/sort-colors)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/075-sort-colors/sort-colors.cpp)||Medium|

|76|[minimum-window-substring](https://leetcode.com/problems/minimum-window-substring)|||Hard|

|77|[combinations](https://leetcode.com/problems/combinations)|||Medium|

|78|[subsets](https://leetcode.com/problems/subsets)|||Medium|

|79|[word-search](https://leetcode.com/problems/word-search)|||Medium|

|80|[remove-duplicates-from-sorted-array-ii](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii)|||Medium|

|81|[search-in-rotated-sorted-array-ii](https://leetcode.com/problems/search-in-rotated-sorted-array-ii)|||Medium|

|82|[remove-duplicates-from-sorted-list-ii](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii)|||Medium|

|83|[remove-duplicates-from-sorted-list](https://leetcode.com/problems/remove-duplicates-from-sorted-list)||[:memo:](https://leetcode.com/articles/remove-duplicates-from-sorted-list/)|Easy|

|84|[largest-rectangle-in-histogram](https://leetcode.com/problems/largest-rectangle-in-histogram)||[:memo:](https://leetcode.com/articles/largest-rectangle-in-histogram/)|Hard|

|85|[maximal-rectangle](https://leetcode.com/problems/maximal-rectangle)|||Hard|

|86|[partition-list](https://leetcode.com/problems/partition-list)|||Medium|

|87|[scramble-string](https://leetcode.com/problems/scramble-string)|||Hard|

|88|[merge-sorted-array](https://leetcode.com/problems/merge-sorted-array)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/088-merge-sorted-array/merge-sorted-array.cpp)||Easy|

|89|[gray-code](https://leetcode.com/problems/gray-code)|||Medium|

|90|[subsets-ii](https://leetcode.com/problems/subsets-ii)|||Medium|

|91|[decode-ways](https://leetcode.com/problems/decode-ways)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/091-decode-ways/decode-ways.cpp)||Medium|

|92|[reverse-linked-list-ii](https://leetcode.com/problems/reverse-linked-list-ii)|||Medium|

|93|[restore-ip-addresses](https://leetcode.com/problems/restore-ip-addresses)|||Medium|

|94|[binary-tree-inorder-traversal](https://leetcode.com/problems/binary-tree-inorder-traversal)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/094-binary-tree-inorder-traversal/binary-tree-inorder-traversal.cpp)|[:memo:](https://leetcode.com/articles/binary-tree-inorder-traversal/)|Medium|

|95|[unique-binary-search-trees-ii](https://leetcode.com/problems/unique-binary-search-trees-ii)|||Medium|

|96|[unique-binary-search-trees](https://leetcode.com/problems/unique-binary-search-trees)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/096-unique-binary-search-trees/unique-binary-search-trees.cpp)||Medium|

|97|[interleaving-string](https://leetcode.com/problems/interleaving-string)||[:memo:](https://leetcode.com/articles/interleaving-strings/)|Hard|

|98|[validate-binary-search-tree](https://leetcode.com/problems/validate-binary-search-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/098-validate-binary-search-tree/validate-binary-search-tree.cpp)||Medium|

|99|[recover-binary-search-tree](https://leetcode.com/problems/recover-binary-search-tree)|||Hard|

|100|[same-tree](https://leetcode.com/problems/same-tree)|||Easy|

|101|[symmetric-tree](https://leetcode.com/problems/symmetric-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/101-symmetric-tree/symmetric-tree.cpp)|[:memo:](https://leetcode.com/articles/symmetric-tree/)|Easy|

|102|[binary-tree-level-order-traversal](https://leetcode.com/problems/binary-tree-level-order-traversal)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/102-binary-tree-level-order-traversal/binary-tree-level-order-traversal.cpp) [Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/102-binary-tree-level-order-traversal/binary-tree-level-order-traversal.swift)||Medium|

|103|[binary-tree-zigzag-level-order-traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal)|||Medium|

|104|[maximum-depth-of-binary-tree](https://leetcode.com/problems/maximum-depth-of-binary-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/104-maximum-depth-of-binary-tree/maximum-depth-of-binary-tree.cpp)||Easy|

|105|[construct-binary-tree-from-preorder-and-inorder-traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal)|||Medium|

|106|[construct-binary-tree-from-inorder-and-postorder-traversal](https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal)|||Medium|

|107|[binary-tree-level-order-traversal-ii](https://leetcode.com/problems/binary-tree-level-order-traversal-ii)|||Easy|

|108|[convert-sorted-array-to-binary-search-tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/108-convert-sorted-array-to-binary-search-tree/convert-sorted-array-to-binary-search-tree.cpp)||Easy|

|109|[convert-sorted-list-to-binary-search-tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree)|||Medium|

|110|[balanced-binary-tree](https://leetcode.com/problems/balanced-binary-tree)|||Easy|

|111|[minimum-depth-of-binary-tree](https://leetcode.com/problems/minimum-depth-of-binary-tree)|||Easy|

|112|[path-sum](https://leetcode.com/problems/path-sum)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/112-path-sum/path-sum.cpp)||Easy|

|113|[path-sum-ii](https://leetcode.com/problems/path-sum-ii)|||Medium|

|114|[flatten-binary-tree-to-linked-list](https://leetcode.com/problems/flatten-binary-tree-to-linked-list)|||Medium|

|115|[distinct-subsequences](https://leetcode.com/problems/distinct-subsequences)|||Hard|

|116|[populating-next-right-pointers-in-each-node](https://leetcode.com/problems/populating-next-right-pointers-in-each-node)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/116-populating-next-right-pointers-in-each-node/populating-next-right-pointers-in-each-node.cpp)||Medium|

|117|[populating-next-right-pointers-in-each-node-ii](https://leetcode.com/problems/populating-next-right-pointers-in-each-node-ii)|||Medium|

|118|[pascals-triangle](https://leetcode.com/problems/pascals-triangle)||[:memo:](https://leetcode.com/articles/pascals-triangle/)|Easy|

|119|[pascals-triangle-ii](https://leetcode.com/problems/pascals-triangle-ii)|||Easy|

|120|[triangle](https://leetcode.com/problems/triangle)|||Medium|

|121|[best-time-to-buy-and-sell-stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/121-best-time-to-buy-and-sell-stock/best-time-to-buy-and-sell-stock.cpp)|[:memo:](https://leetcode.com/articles/best-time-to-buy-and-sell-stock/)|Easy|

|122|[best-time-to-buy-and-sell-stock-ii](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii)||[:memo:](https://leetcode.com/articles/best-time-to-buy-and-sell-stock-ii/)|Easy|

|123|[best-time-to-buy-and-sell-stock-iii](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii)|||Hard|

|124|[binary-tree-maximum-path-sum](https://leetcode.com/problems/binary-tree-maximum-path-sum)|||Hard|

|125|[valid-palindrome](https://leetcode.com/problems/valid-palindrome)|||Easy|

|126|[word-ladder-ii](https://leetcode.com/problems/word-ladder-ii)|||Hard|

|127|[word-ladder](https://leetcode.com/problems/word-ladder)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/127-word-ladder/word-ladder.cpp)||Medium|

|128|[longest-consecutive-sequence](https://leetcode.com/problems/longest-consecutive-sequence)||[:memo:](https://leetcode.com/articles/longest-consecutive-sequence/)|Hard|

|129|[sum-root-to-leaf-numbers](https://leetcode.com/problems/sum-root-to-leaf-numbers)|||Medium|

|130|[surrounded-regions](https://leetcode.com/problems/surrounded-regions)|||Medium|

|131|[palindrome-partitioning](https://leetcode.com/problems/palindrome-partitioning)|||Medium|

|132|[palindrome-partitioning-ii](https://leetcode.com/problems/palindrome-partitioning-ii)|||Hard|

|133|[clone-graph](https://leetcode.com/problems/clone-graph)|||Medium|

|134|[gas-station](https://leetcode.com/problems/gas-station)|||Medium|

|135|[candy](https://leetcode.com/problems/candy)||[:memo:](https://leetcode.com/articles/candy/)|Hard|

|136|[single-number](https://leetcode.com/problems/single-number)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/136-single-number/single-number.cpp)|[:memo:](https://leetcode.com/articles/single-number/)|Easy|

|137|[single-number-ii](https://leetcode.com/problems/single-number-ii)|||Medium|

|138|[copy-list-with-random-pointer](https://leetcode.com/problems/copy-list-with-random-pointer)|||Medium|

|139|[word-break](https://leetcode.com/problems/word-break)||[:memo:](https://leetcode.com/articles/word-break/)|Medium|

|140|[word-break-ii](https://leetcode.com/problems/word-break-ii)||[:memo:](https://leetcode.com/articles/word-break-ii/)|Hard|

|141|[linked-list-cycle](https://leetcode.com/problems/linked-list-cycle)||[:memo:](https://leetcode.com/articles/linked-list-cycle/)|Easy|

|142|[linked-list-cycle-ii](https://leetcode.com/problems/linked-list-cycle-ii)||[:memo:](https://leetcode.com/articles/linked-list-cycle-ii/)|Medium|

|143|[reorder-list](https://leetcode.com/problems/reorder-list)|||Medium|

|144|[binary-tree-preorder-traversal](https://leetcode.com/problems/binary-tree-preorder-traversal)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/144-binary-tree-preorder-traversal/binary-tree-preorder-traversal.cpp)||Medium|

|145|[binary-tree-postorder-traversal](https://leetcode.com/problems/binary-tree-postorder-traversal)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/145-binary-tree-postorder-traversal/binary-tree-postorder-traversal.cpp)||Hard|

|146|[lru-cache](https://leetcode.com/problems/lru-cache)|||Hard|

|147|[insertion-sort-list](https://leetcode.com/problems/insertion-sort-list)|||Medium|

|148|[sort-list](https://leetcode.com/problems/sort-list)|||Medium|

|149|[max-points-on-a-line](https://leetcode.com/problems/max-points-on-a-line)|||Hard|

|150|[evaluate-reverse-polish-notation](https://leetcode.com/problems/evaluate-reverse-polish-notation)|||Medium|

|151|[reverse-words-in-a-string](https://leetcode.com/problems/reverse-words-in-a-string)|||Medium|

|152|[maximum-product-subarray](https://leetcode.com/problems/maximum-product-subarray)|||Medium|

|153|[find-minimum-in-rotated-sorted-array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/153-find-minimum-in-rotated-sorted-array/find-minimum-in-rotated-sorted-array.cpp)||Medium|

|154|[find-minimum-in-rotated-sorted-array-ii](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array-ii)|||Hard|

|155|[min-stack](https://leetcode.com/problems/min-stack)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/155-min-stack/min-stack.cpp)||Easy|

|156|[binary-tree-upside-down](https://leetcode.com/problems/binary-tree-upside-down)|:lock:||Medium|

|157|[read-n-characters-given-read4](https://leetcode.com/problems/read-n-characters-given-read4)|:lock:||Easy|

|158|[read-n-characters-given-read4-ii-call-multiple-times](https://leetcode.com/problems/read-n-characters-given-read4-ii-call-multiple-times)|:lock:||Hard|

|159|[longest-substring-with-at-most-two-distinct-characters](https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters)|:lock:||Hard|

|160|[intersection-of-two-linked-lists](https://leetcode.com/problems/intersection-of-two-linked-lists)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/160-intersection-of-two-linked-lists/intersection-of-two-linked-lists.cpp)|[:memo:](https://leetcode.com/articles/intersection-of-two-linked-lists/)|Easy|

|161|[one-edit-distance](https://leetcode.com/problems/one-edit-distance)|:lock:||Medium|

|162|[find-peak-element](https://leetcode.com/problems/find-peak-element)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/162-find-peak-element/find-peak-element.cpp)|[:memo:](https://leetcode.com/articles/find-peak-element/)|Medium|

|163|[missing-ranges](https://leetcode.com/problems/missing-ranges)|:lock:||Medium|

|164|[maximum-gap](https://leetcode.com/problems/maximum-gap)||[:memo:](https://leetcode.com/articles/maximum-gap/)|Hard|

|165|[compare-version-numbers](https://leetcode.com/problems/compare-version-numbers)|||Medium|

|166|[fraction-to-recurring-decimal](https://leetcode.com/problems/fraction-to-recurring-decimal)||[:memo:](https://leetcode.com/articles/fraction-to-recurring-decimal/)|Medium|

|167|[two-sum-ii-input-array-is-sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/167-two-sum-ii-input-array-is-sorted/two-sum-ii-input-array-is-sorted.swift)|[:memo:](https://leetcode.com/articles/two-sum-ii-input-array-is-sorted/)|Easy|

|168|[excel-sheet-column-title](https://leetcode.com/problems/excel-sheet-column-title)|||Easy|

|169|[majority-element](https://leetcode.com/problems/majority-element)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/169-majority-element/majority-element.cpp)|[:memo:](https://leetcode.com/articles/majority-element/)|Easy|

|170|[two-sum-iii-data-structure-design](https://leetcode.com/problems/two-sum-iii-data-structure-design)|:lock:||Easy|

|171|[excel-sheet-column-number](https://leetcode.com/problems/excel-sheet-column-number)|||Easy|

|172|[factorial-trailing-zeroes](https://leetcode.com/problems/factorial-trailing-zeroes)|||Easy|

|173|[binary-search-tree-iterator](https://leetcode.com/problems/binary-search-tree-iterator)|||Medium|

|174|[dungeon-game](https://leetcode.com/problems/dungeon-game)|||Hard|

|179|[largest-number](https://leetcode.com/problems/largest-number)||[:memo:](https://leetcode.com/articles/largest-number/)|Medium|

|186|[reverse-words-in-a-string-ii](https://leetcode.com/problems/reverse-words-in-a-string-ii)|:lock:||Medium|

|187|[repeated-dna-sequences](https://leetcode.com/problems/repeated-dna-sequences)|||Medium|

|188|[best-time-to-buy-and-sell-stock-iv](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iv)|||Hard|

|189|[rotate-array](https://leetcode.com/problems/rotate-array)||[:memo:](https://leetcode.com/articles/rotate-array/)|Easy|

|190|[reverse-bits](https://leetcode.com/problems/reverse-bits)|||Easy|

|191|[number-of-1-bits](https://leetcode.com/problems/number-of-1-bits)||[:memo:](https://leetcode.com/articles/number-1-bits/)|Easy|

|198|[house-robber](https://leetcode.com/problems/house-robber)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/198-house-robber/house-robber.cpp)|[:memo:](https://leetcode.com/articles/house-robber/)|Easy|

|199|[binary-tree-right-side-view](https://leetcode.com/problems/binary-tree-right-side-view)||[:memo:](https://leetcode.com/articles/binary-tree-right-side-view/)|Medium|

|200|[number-of-islands](https://leetcode.com/problems/number-of-islands)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/200-number-of-islands/number-of-islands.cpp)|[:memo:](https://leetcode.com/articles/number-of-islands/)|Medium|

|201|[bitwise-and-of-numbers-range](https://leetcode.com/problems/bitwise-and-of-numbers-range)|||Medium|

|202|[happy-number](https://leetcode.com/problems/happy-number)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/202-happy-number/happy-number.cpp)||Easy|

|203|[remove-linked-list-elements](https://leetcode.com/problems/remove-linked-list-elements)|||Easy|

|204|[count-primes](https://leetcode.com/problems/count-primes)|||Easy|

|205|[isomorphic-strings](https://leetcode.com/problems/isomorphic-strings)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/205-isomorphic-strings/isomorphic-strings.cpp)||Easy|

|206|[reverse-linked-list](https://leetcode.com/problems/reverse-linked-list)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/206-reverse-linked-list/reverse-linked-list.cpp)|[:memo:](https://leetcode.com/articles/reverse-linked-list/)|Easy|

|207|[course-schedule](https://leetcode.com/problems/course-schedule)|||Medium|

|208|[implement-trie-prefix-tree](https://leetcode.com/problems/implement-trie-prefix-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/208-implement-trie-prefix-tree/implement-trie-prefix-tree.cpp)|[:memo:](https://leetcode.com/articles/implement-trie-prefix-tree/)|Medium|

|209|[minimum-size-subarray-sum](https://leetcode.com/problems/minimum-size-subarray-sum)||[:memo:](https://leetcode.com/articles/minimum-size-subarray-sum/)|Medium|

|210|[course-schedule-ii](https://leetcode.com/problems/course-schedule-ii)|||Medium|

|211|[add-and-search-word-data-structure-design](https://leetcode.com/problems/add-and-search-word-data-structure-design)|||Medium|

|212|[word-search-ii](https://leetcode.com/problems/word-search-ii)|||Hard|

|213|[house-robber-ii](https://leetcode.com/problems/house-robber-ii)|||Medium|

|214|[shortest-palindrome](https://leetcode.com/problems/shortest-palindrome)||[:memo:](https://leetcode.com/articles/shortest-palindrome/)|Hard|

|215|[kth-largest-element-in-an-array](https://leetcode.com/problems/kth-largest-element-in-an-array)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/215-kth-largest-element-in-an-array/kth-largest-element-in-an-array.cpp)||Medium|

|216|[combination-sum-iii](https://leetcode.com/problems/combination-sum-iii)|||Medium|

|217|[contains-duplicate](https://leetcode.com/problems/contains-duplicate)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/217-contains-duplicate/contains-duplicate.cpp)|[:memo:](https://leetcode.com/articles/contains-duplicate/)|Easy|

|218|[the-skyline-problem](https://leetcode.com/problems/the-skyline-problem)|||Hard|

|219|[contains-duplicate-ii](https://leetcode.com/problems/contains-duplicate-ii)||[:memo:](https://leetcode.com/articles/contains-duplicate-ii/)|Easy|

|220|[contains-duplicate-iii](https://leetcode.com/problems/contains-duplicate-iii)||[:memo:](https://leetcode.com/articles/contains-duplicate-iii/)|Medium|

|221|[maximal-square](https://leetcode.com/problems/maximal-square)||[:memo:](https://leetcode.com/articles/maximal-square/)|Medium|

|222|[count-complete-tree-nodes](https://leetcode.com/problems/count-complete-tree-nodes)|||Medium|

|223|[rectangle-area](https://leetcode.com/problems/rectangle-area)|||Medium|

|224|[basic-calculator](https://leetcode.com/problems/basic-calculator)|||Hard|

|225|[implement-stack-using-queues](https://leetcode.com/problems/implement-stack-using-queues)||[:memo:](https://leetcode.com/articles/implement-stack-using-queues/)|Easy|

|226|[invert-binary-tree](https://leetcode.com/problems/invert-binary-tree)||[:memo:](https://leetcode.com/articles/invert-binary-tree/)|Easy|

|227|[basic-calculator-ii](https://leetcode.com/problems/basic-calculator-ii)|||Medium|

|228|[summary-ranges](https://leetcode.com/problems/summary-ranges)||[:memo:](https://leetcode.com/articles/summary-ranges/)|Medium|

|229|[majority-element-ii](https://leetcode.com/problems/majority-element-ii)|||Medium|

|230|[kth-smallest-element-in-a-bst](https://leetcode.com/problems/kth-smallest-element-in-a-bst)|||Medium|

|231|[power-of-two](https://leetcode.com/problems/power-of-two)|||Easy|

|232|[implement-queue-using-stacks](https://leetcode.com/problems/implement-queue-using-stacks)||[:memo:](https://leetcode.com/articles/implement-queue-using-stacks/)|Easy|

|233|[number-of-digit-one](https://leetcode.com/problems/number-of-digit-one)||[:memo:](https://leetcode.com/articles/number-of-digit-one/)|Hard|

|234|[palindrome-linked-list](https://leetcode.com/problems/palindrome-linked-list)|||Easy|

|235|[lowest-common-ancestor-of-a-binary-search-tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree)|||Easy|

|236|[lowest-common-ancestor-of-a-binary-tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree)|||Medium|

|237|[delete-node-in-a-linked-list](https://leetcode.com/problems/delete-node-in-a-linked-list)||[:memo:](https://leetcode.com/articles/delete-node-linked-list/)|Easy|

|238|[product-of-array-except-self](https://leetcode.com/problems/product-of-array-except-self)|||Medium|

|239|[sliding-window-maximum](https://leetcode.com/problems/sliding-window-maximum)|||Hard|

|240|[search-a-2d-matrix-ii](https://leetcode.com/problems/search-a-2d-matrix-ii)||[:memo:](https://leetcode.com/articles/search-a-2d-matrix-ii/)|Medium|

|241|[different-ways-to-add-parentheses](https://leetcode.com/problems/different-ways-to-add-parentheses)|||Medium|

|242|[valid-anagram](https://leetcode.com/problems/valid-anagram)||[:memo:](https://leetcode.com/articles/valid-anagram/)|Easy|

|243|[shortest-word-distance](https://leetcode.com/problems/shortest-word-distance)|:lock:|[:memo:](https://leetcode.com/articles/shortest-word-distance/)|Easy|

|244|[shortest-word-distance-ii](https://leetcode.com/problems/shortest-word-distance-ii)|:lock:||Medium|

|245|[shortest-word-distance-iii](https://leetcode.com/problems/shortest-word-distance-iii)|:lock:||Medium|

|246|[strobogrammatic-number](https://leetcode.com/problems/strobogrammatic-number)|:lock:||Easy|

|247|[strobogrammatic-number-ii](https://leetcode.com/problems/strobogrammatic-number-ii)|:lock:||Medium|

|248|[strobogrammatic-number-iii](https://leetcode.com/problems/strobogrammatic-number-iii)|:lock:||Hard|

|249|[group-shifted-strings](https://leetcode.com/problems/group-shifted-strings)|:lock:||Medium|

|250|[count-univalue-subtrees](https://leetcode.com/problems/count-univalue-subtrees)|:lock:||Medium|

|251|[flatten-2d-vector](https://leetcode.com/problems/flatten-2d-vector)|:lock:||Medium|

|252|[meeting-rooms](https://leetcode.com/problems/meeting-rooms)|:lock:|[:memo:](https://leetcode.com/articles/meeting-rooms/)|Easy|

|253|[meeting-rooms-ii](https://leetcode.com/problems/meeting-rooms-ii)|:lock:||Medium|

|254|[factor-combinations](https://leetcode.com/problems/factor-combinations)|:lock:||Medium|

|255|[verify-preorder-sequence-in-binary-search-tree](https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree)|:lock:||Medium|

|256|[paint-house](https://leetcode.com/problems/paint-house)|:lock:||Easy|

|257|[binary-tree-paths](https://leetcode.com/problems/binary-tree-paths)|||Easy|

|258|[add-digits](https://leetcode.com/problems/add-digits)|||Easy|

|259|[3sum-smaller](https://leetcode.com/problems/3sum-smaller)|:lock:|[:memo:](https://leetcode.com/articles/3sum-smaller/)|Medium|

|260|[single-number-iii](https://leetcode.com/problems/single-number-iii)|||Medium|

|261|[graph-valid-tree](https://leetcode.com/problems/graph-valid-tree)|:lock:||Medium|

|263|[ugly-number](https://leetcode.com/problems/ugly-number)|||Easy|

|264|[ugly-number-ii](https://leetcode.com/problems/ugly-number-ii)|||Medium|

|265|[paint-house-ii](https://leetcode.com/problems/paint-house-ii)|:lock:||Hard|

|266|[palindrome-permutation](https://leetcode.com/problems/palindrome-permutation)|:lock:|[:memo:](https://leetcode.com/articles/palindrome-permutation/)|Easy|

|267|[palindrome-permutation-ii](https://leetcode.com/problems/palindrome-permutation-ii)|:lock:|[:memo:](https://leetcode.com/articles/palindrome-permutation-ii/)|Medium|

|268|[missing-number](https://leetcode.com/problems/missing-number)||[:memo:](https://leetcode.com/articles/missing-number/)|Easy|

|269|[alien-dictionary](https://leetcode.com/problems/alien-dictionary)|:lock:||Hard|

|270|[closest-binary-search-tree-value](https://leetcode.com/problems/closest-binary-search-tree-value)|:lock:||Easy|

|271|[encode-and-decode-strings](https://leetcode.com/problems/encode-and-decode-strings)|:lock:||Medium|

|272|[closest-binary-search-tree-value-ii](https://leetcode.com/problems/closest-binary-search-tree-value-ii)|:lock:||Hard|

|273|[integer-to-english-words](https://leetcode.com/problems/integer-to-english-words)|||Hard|

|274|[h-index](https://leetcode.com/problems/h-index)||[:memo:](https://leetcode.com/articles/h-index/)|Medium|

|275|[h-index-ii](https://leetcode.com/problems/h-index-ii)|||Medium|

|276|[paint-fence](https://leetcode.com/problems/paint-fence)|:lock:||Easy|

|277|[find-the-celebrity](https://leetcode.com/problems/find-the-celebrity)|:lock:||Medium|

|278|[first-bad-version](https://leetcode.com/problems/first-bad-version)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/278-first-bad-version/first-bad-version.cpp)|[:memo:](https://leetcode.com/articles/first-bad-version/)|Easy|

|279|[perfect-squares](https://leetcode.com/problems/perfect-squares)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/279-perfect-squares/perfect-squares.cpp) [Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/279-perfect-squares/perfect-squares.swift)||Medium|

|280|[wiggle-sort](https://leetcode.com/problems/wiggle-sort)|:lock:|[:memo:](https://leetcode.com/articles/wiggle-sort/)|Medium|

|281|[zigzag-iterator](https://leetcode.com/problems/zigzag-iterator)|:lock:||Medium|

|282|[expression-add-operators](https://leetcode.com/problems/expression-add-operators)|||Hard|

|283|[move-zeroes](https://leetcode.com/problems/move-zeroes)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/283-move-zeroes/move-zeroes.cpp)|[:memo:](https://leetcode.com/articles/move-zeroes/)|Easy|

|284|[peeking-iterator](https://leetcode.com/problems/peeking-iterator)|||Medium|

|285|[inorder-successor-in-bst](https://leetcode.com/problems/inorder-successor-in-bst)|:lock:||Medium|

|286|[walls-and-gates](https://leetcode.com/problems/walls-and-gates)|:lock:|[:memo:](https://leetcode.com/articles/walls-and-gates/)|Medium|

|287|[find-the-duplicate-number](https://leetcode.com/problems/find-the-duplicate-number)||[:memo:](https://leetcode.com/articles/find-the-duplicate-number/)|Medium|

|288|[unique-word-abbreviation](https://leetcode.com/problems/unique-word-abbreviation)|:lock:|[:memo:](https://leetcode.com/articles/unique-word-abbreviation/)|Medium|

|289|[game-of-life](https://leetcode.com/problems/game-of-life)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/289-game-of-life/game-of-life.cpp)||Medium|

|290|[word-pattern](https://leetcode.com/problems/word-pattern)|||Easy|

|291|[word-pattern-ii](https://leetcode.com/problems/word-pattern-ii)|:lock:||Hard|

|292|[nim-game](https://leetcode.com/problems/nim-game)||[:memo:](https://leetcode.com/articles/nim-game/)|Easy|

|293|[flip-game](https://leetcode.com/problems/flip-game)|:lock:||Easy|

|294|[flip-game-ii](https://leetcode.com/problems/flip-game-ii)|:lock:||Medium|

|295|[find-median-from-data-stream](https://leetcode.com/problems/find-median-from-data-stream)||[:memo:](https://leetcode.com/articles/find-median-from-data-stream/)|Hard|

|296|[best-meeting-point](https://leetcode.com/problems/best-meeting-point)|:lock:|[:memo:](https://leetcode.com/articles/best-meeting-point/)|Hard|

|297|[serialize-and-deserialize-binary-tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/297-serialize-and-deserialize-binary-tree/serialize-and-deserialize-binary-tree.cpp)||Hard|

|298|[binary-tree-longest-consecutive-sequence](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence)|:lock:|[:memo:](https://leetcode.com/articles/binary-tree-longest-consecutive-sequence/)|Medium|

|299|[bulls-and-cows](https://leetcode.com/problems/bulls-and-cows)|||Medium|

|300|[longest-increasing-subsequence](https://leetcode.com/problems/longest-increasing-subsequence)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/300-longest-increasing-subsequence/longest-increasing-subsequence.cpp)|[:memo:](https://leetcode.com/articles/longest-increasing-subsequence/)|Medium|

|301|[remove-invalid-parentheses](https://leetcode.com/problems/remove-invalid-parentheses)|||Hard|

|302|[smallest-rectangle-enclosing-black-pixels](https://leetcode.com/problems/smallest-rectangle-enclosing-black-pixels)|:lock:|[:memo:](https://leetcode.com/articles/smallest-rectangle-enclosing-black-pixels/)|Hard|

|303|[range-sum-query-immutable](https://leetcode.com/problems/range-sum-query-immutable)||[:memo:](https://leetcode.com/articles/range-sum-query-immutable/)|Easy|

|304|[range-sum-query-2d-immutable](https://leetcode.com/problems/range-sum-query-2d-immutable)||[:memo:](https://leetcode.com/articles/range-sum-query-2d-immutable/)|Medium|

|305|[number-of-islands-ii](https://leetcode.com/problems/number-of-islands-ii)|:lock:|[:memo:](https://leetcode.com/articles/number-of-islands-ii/)|Hard|

|306|[additive-number](https://leetcode.com/problems/additive-number)|||Medium|

|307|[range-sum-query-mutable](https://leetcode.com/problems/range-sum-query-mutable)||[:memo:](https://leetcode.com/articles/range-sum-query-mutable/)|Medium|

|308|[range-sum-query-2d-mutable](https://leetcode.com/problems/range-sum-query-2d-mutable)|:lock:||Hard|

|309|[best-time-to-buy-and-sell-stock-with-cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown)|||Medium|

|310|[minimum-height-trees](https://leetcode.com/problems/minimum-height-trees)|||Medium|

|311|[sparse-matrix-multiplication](https://leetcode.com/problems/sparse-matrix-multiplication)|:lock:||Medium|

|312|[burst-balloons](https://leetcode.com/problems/burst-balloons)|||Hard|

|313|[super-ugly-number](https://leetcode.com/problems/super-ugly-number)|||Medium|

|314|[binary-tree-vertical-order-traversal](https://leetcode.com/problems/binary-tree-vertical-order-traversal)|:lock:||Medium|

|315|[count-of-smaller-numbers-after-self](https://leetcode.com/problems/count-of-smaller-numbers-after-self)|||Hard|

|316|[remove-duplicate-letters](https://leetcode.com/problems/remove-duplicate-letters)|||Hard|

|317|[shortest-distance-from-all-buildings](https://leetcode.com/problems/shortest-distance-from-all-buildings)|:lock:||Hard|

|318|[maximum-product-of-word-lengths](https://leetcode.com/problems/maximum-product-of-word-lengths)|||Medium|

|319|[bulb-switcher](https://leetcode.com/problems/bulb-switcher)|||Medium|

|320|[generalized-abbreviation](https://leetcode.com/problems/generalized-abbreviation)|:lock:|[:memo:](https://leetcode.com/articles/generalized-abbreviation/)|Medium|

|321|[create-maximum-number](https://leetcode.com/problems/create-maximum-number)|||Hard|

|322|[coin-change](https://leetcode.com/problems/coin-change)|[Swift](https://github.com/fancymax/Leetcode_Swift/blob/master/322-coin-change/coin-change.swift) [Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/322-coin-change/coin-change.cpp)|[:memo:](https://leetcode.com/articles/coin-change/)|Medium|

|323|[number-of-connected-components-in-an-undirected-graph](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph)|:lock:||Medium|

|324|[wiggle-sort-ii](https://leetcode.com/problems/wiggle-sort-ii)|||Medium|

|325|[maximum-size-subarray-sum-equals-k](https://leetcode.com/problems/maximum-size-subarray-sum-equals-k)|:lock:||Medium|

|326|[power-of-three](https://leetcode.com/problems/power-of-three)||[:memo:](https://leetcode.com/articles/power-of-three/)|Easy|

|327|[count-of-range-sum](https://leetcode.com/problems/count-of-range-sum)|||Hard|

|328|[odd-even-linked-list](https://leetcode.com/problems/odd-even-linked-list)||[:memo:](https://leetcode.com/articles/odd-even-linked-list/)|Medium|

|329|[longest-increasing-path-in-a-matrix](https://leetcode.com/problems/longest-increasing-path-in-a-matrix)||[:memo:](https://leetcode.com/articles/longest-increasing-path-matrix/)|Hard|

|330|[patching-array](https://leetcode.com/problems/patching-array)||[:memo:](https://leetcode.com/articles/patching-array/)|Hard|

|331|[verify-preorder-serialization-of-a-binary-tree](https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree)|||Medium|

|332|[reconstruct-itinerary](https://leetcode.com/problems/reconstruct-itinerary)|||Medium|

|333|[largest-bst-subtree](https://leetcode.com/problems/largest-bst-subtree)|:lock:||Medium|

|334|[increasing-triplet-subsequence](https://leetcode.com/problems/increasing-triplet-subsequence)|||Medium|

|335|[self-crossing](https://leetcode.com/problems/self-crossing)|||Hard|

|336|[palindrome-pairs](https://leetcode.com/problems/palindrome-pairs)|||Hard|

|337|[house-robber-iii](https://leetcode.com/problems/house-robber-iii)|||Medium|

|338|[counting-bits](https://leetcode.com/problems/counting-bits)||[:memo:](https://leetcode.com/articles/counting-bits/)|Medium|

|339|[nested-list-weight-sum](https://leetcode.com/problems/nested-list-weight-sum)|:lock:|[:memo:](https://leetcode.com/articles/nested-list-weight-sum/)|Easy|

|340|[longest-substring-with-at-most-k-distinct-characters](https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters)|:lock:||Hard|

|341|[flatten-nested-list-iterator](https://leetcode.com/problems/flatten-nested-list-iterator)|||Medium|

|342|[power-of-four](https://leetcode.com/problems/power-of-four)|||Easy|

|343|[integer-break](https://leetcode.com/problems/integer-break)|||Medium|

|344|[reverse-string](https://leetcode.com/problems/reverse-string)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/344-reverse-string/reverse-string.cpp)||Easy|

|345|[reverse-vowels-of-a-string](https://leetcode.com/problems/reverse-vowels-of-a-string)|||Easy|

|346|[moving-average-from-data-stream](https://leetcode.com/problems/moving-average-from-data-stream)|:lock:||Easy|

|347|[top-k-frequent-elements](https://leetcode.com/problems/top-k-frequent-elements)|||Medium|

|348|[design-tic-tac-toe](https://leetcode.com/problems/design-tic-tac-toe)|:lock:||Medium|

|349|[intersection-of-two-arrays](https://leetcode.com/problems/intersection-of-two-arrays)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/349-intersection-of-two-arrays/intersection-of-two-arrays.cpp)||Easy|

|350|[intersection-of-two-arrays-ii](https://leetcode.com/problems/intersection-of-two-arrays-ii)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/350-intersection-of-two-arrays-ii/intersection-of-two-arrays-ii.cpp)||Easy|

|351|[android-unlock-patterns](https://leetcode.com/problems/android-unlock-patterns)|:lock:|[:memo:](https://leetcode.com/articles/android-unlock-patterns/)|Medium|

|352|[data-stream-as-disjoint-intervals](https://leetcode.com/problems/data-stream-as-disjoint-intervals)|||Hard|

|353|[design-snake-game](https://leetcode.com/problems/design-snake-game)|:lock:||Medium|

|354|[russian-doll-envelopes](https://leetcode.com/problems/russian-doll-envelopes)|||Hard|

|355|[design-twitter](https://leetcode.com/problems/design-twitter)|||Medium|

|356|[line-reflection](https://leetcode.com/problems/line-reflection)|:lock:||Medium|

|357|[count-numbers-with-unique-digits](https://leetcode.com/problems/count-numbers-with-unique-digits)|||Medium|

|358|[rearrange-string-k-distance-apart](https://leetcode.com/problems/rearrange-string-k-distance-apart)|:lock:||Hard|

|359|[logger-rate-limiter](https://leetcode.com/problems/logger-rate-limiter)|:lock:||Easy|

|360|[sort-transformed-array](https://leetcode.com/problems/sort-transformed-array)|:lock:||Medium|

|361|[bomb-enemy](https://leetcode.com/problems/bomb-enemy)|:lock:||Medium|

|362|[design-hit-counter](https://leetcode.com/problems/design-hit-counter)|:lock:||Medium|

|363|[max-sum-of-rectangle-no-larger-than-k](https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k)|||Hard|

|364|[nested-list-weight-sum-ii](https://leetcode.com/problems/nested-list-weight-sum-ii)|:lock:||Medium|

|365|[water-and-jug-problem](https://leetcode.com/problems/water-and-jug-problem)|||Medium|

|366|[find-leaves-of-binary-tree](https://leetcode.com/problems/find-leaves-of-binary-tree)|:lock:||Medium|

|367|[valid-perfect-square](https://leetcode.com/problems/valid-perfect-square)|||Easy|

|368|[largest-divisible-subset](https://leetcode.com/problems/largest-divisible-subset)|||Medium|

|369|[plus-one-linked-list](https://leetcode.com/problems/plus-one-linked-list)|:lock:||Medium|

|370|[range-addition](https://leetcode.com/problems/range-addition)|:lock:|[:memo:](https://leetcode.com/articles/range-addition/)|Medium|

|371|[sum-of-two-integers](https://leetcode.com/problems/sum-of-two-integers)|||Easy|

|372|[super-pow](https://leetcode.com/problems/super-pow)|||Medium|

|373|[find-k-pairs-with-smallest-sums](https://leetcode.com/problems/find-k-pairs-with-smallest-sums)|||Medium|

|374|[guess-number-higher-or-lower](https://leetcode.com/problems/guess-number-higher-or-lower)||[:memo:](https://leetcode.com/articles/guess-number-higher-or-lower/)|Easy|

|375|[guess-number-higher-or-lower-ii](https://leetcode.com/problems/guess-number-higher-or-lower-ii)||[:memo:](https://leetcode.com/articles/guess-number-higher-or-lower-ii/)|Medium|

|376|[wiggle-subsequence](https://leetcode.com/problems/wiggle-subsequence)||[:memo:](https://leetcode.com/articles/wiggle-subsequence/)|Medium|

|377|[combination-sum-iv](https://leetcode.com/problems/combination-sum-iv)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/377-combination-sum-iv/combination-sum-iv.cpp)||Medium|

|378|[kth-smallest-element-in-a-sorted-matrix](https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix)|||Medium|

|379|[design-phone-directory](https://leetcode.com/problems/design-phone-directory)|:lock:||Medium|

|380|[insert-delete-getrandom-o1](https://leetcode.com/problems/insert-delete-getrandom-o1)|||Medium|

|381|[insert-delete-getrandom-o1-duplicates-allowed](https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed)|||Hard|

|382|[linked-list-random-node](https://leetcode.com/problems/linked-list-random-node)|||Medium|

|383|[ransom-note](https://leetcode.com/problems/ransom-note)|||Easy|

|384|[shuffle-an-array](https://leetcode.com/problems/shuffle-an-array)||[:memo:](https://leetcode.com/articles/shuffle-an-array/)|Medium|

|385|[mini-parser](https://leetcode.com/problems/mini-parser)|||Medium|

|386|[lexicographical-numbers](https://leetcode.com/problems/lexicographical-numbers)|||Medium|

|387|[first-unique-character-in-a-string](https://leetcode.com/problems/first-unique-character-in-a-string)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/387-first-unique-character-in-a-string/first-unique-character-in-a-string.cpp)||Easy|

|388|[longest-absolute-file-path](https://leetcode.com/problems/longest-absolute-file-path)|||Medium|

|389|[find-the-difference](https://leetcode.com/problems/find-the-difference)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/389-find-the-difference/find-the-difference.cpp)||Easy|

|390|[elimination-game](https://leetcode.com/problems/elimination-game)|||Medium|

|391|[perfect-rectangle](https://leetcode.com/problems/perfect-rectangle)|||Hard|

|392|[is-subsequence](https://leetcode.com/problems/is-subsequence)|||Medium|

|393|[utf-8-validation](https://leetcode.com/problems/utf-8-validation)|||Medium|

|394|[decode-string](https://leetcode.com/problems/decode-string)|||Medium|

|395|[longest-substring-with-at-least-k-repeating-characters](https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters)|||Medium|

|396|[rotate-function](https://leetcode.com/problems/rotate-function)|||Medium|

|397|[integer-replacement](https://leetcode.com/problems/integer-replacement)|||Medium|

|398|[random-pick-index](https://leetcode.com/problems/random-pick-index)|||Medium|

|399|[evaluate-division](https://leetcode.com/problems/evaluate-division)|||Medium|

|400|[nth-digit](https://leetcode.com/problems/nth-digit)|||Easy|

|401|[binary-watch](https://leetcode.com/problems/binary-watch)|||Easy|

|402|[remove-k-digits](https://leetcode.com/problems/remove-k-digits)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/402-remove-k-digits/remove-k-digits.cpp)||Medium|

|403|[frog-jump](https://leetcode.com/problems/frog-jump)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/403-frog-jump/frog-jump.cpp)|[:memo:](https://leetcode.com/articles/frog-jump/)|Hard|

|404|[sum-of-left-leaves](https://leetcode.com/problems/sum-of-left-leaves)|||Easy|

|405|[convert-a-number-to-hexadecimal](https://leetcode.com/problems/convert-a-number-to-hexadecimal)|||Easy|

|406|[queue-reconstruction-by-height](https://leetcode.com/problems/queue-reconstruction-by-height)|||Medium|

|407|[trapping-rain-water-ii](https://leetcode.com/problems/trapping-rain-water-ii)|||Hard|

|408|[valid-word-abbreviation](https://leetcode.com/problems/valid-word-abbreviation)|:lock:||Easy|

|409|[longest-palindrome](https://leetcode.com/problems/longest-palindrome)||[:memo:](https://leetcode.com/articles/longest-palindrome/)|Easy|

|410|[split-array-largest-sum](https://leetcode.com/problems/split-array-largest-sum)||[:memo:](https://leetcode.com/articles/split-array-largest-sum/)|Hard|

|411|[minimum-unique-word-abbreviation](https://leetcode.com/problems/minimum-unique-word-abbreviation)|:lock:||Hard|

|412|[fizz-buzz](https://leetcode.com/problems/fizz-buzz)|||Easy|

|413|[arithmetic-slices](https://leetcode.com/problems/arithmetic-slices)||[:memo:](https://leetcode.com/articles/arithmetic-slices/)|Medium|

|414|[third-maximum-number](https://leetcode.com/problems/third-maximum-number)|||Easy|

|415|[add-strings](https://leetcode.com/problems/add-strings)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/415-add-strings/add-strings.cpp)||Easy|

|416|[partition-equal-subset-sum](https://leetcode.com/problems/partition-equal-subset-sum)|||Medium|

|417|[pacific-atlantic-water-flow](https://leetcode.com/problems/pacific-atlantic-water-flow)|||Medium|

|418|[sentence-screen-fitting](https://leetcode.com/problems/sentence-screen-fitting)|:lock:||Medium|

|419|[battleships-in-a-board](https://leetcode.com/problems/battleships-in-a-board)|||Medium|

|420|[strong-password-checker](https://leetcode.com/problems/strong-password-checker)|||Hard|

|421|[maximum-xor-of-two-numbers-in-an-array](https://leetcode.com/problems/maximum-xor-of-two-numbers-in-an-array)|||Medium|

|422|[valid-word-square](https://leetcode.com/problems/valid-word-square)|:lock:||Easy|

|423|[reconstruct-original-digits-from-english](https://leetcode.com/problems/reconstruct-original-digits-from-english)|||Medium|

|424|[longest-repeating-character-replacement](https://leetcode.com/problems/longest-repeating-character-replacement)|||Medium|

|425|[word-squares](https://leetcode.com/problems/word-squares)|:lock:||Hard|

|432|[all-oone-data-structure](https://leetcode.com/problems/all-oone-data-structure)|||Hard|

|433|[minimum-genetic-mutation](https://leetcode.com/problems/minimum-genetic-mutation)|||Medium|

|434|[number-of-segments-in-a-string](https://leetcode.com/problems/number-of-segments-in-a-string)||[:memo:](https://leetcode.com/articles/number-of-segments-in-a-string/)|Easy|

|435|[non-overlapping-intervals](https://leetcode.com/problems/non-overlapping-intervals)||[:memo:](https://leetcode.com/articles/non-overlapping-intervals/)|Medium|

|436|[find-right-interval](https://leetcode.com/problems/find-right-interval)||[:memo:](https://leetcode.com/articles/find-right-interval/)|Medium|

|437|[path-sum-iii](https://leetcode.com/problems/path-sum-iii)|||Easy|

|438|[find-all-anagrams-in-a-string](https://leetcode.com/problems/find-all-anagrams-in-a-string)|||Easy|

|439|[ternary-expression-parser](https://leetcode.com/problems/ternary-expression-parser)|:lock:||Medium|

|440|[k-th-smallest-in-lexicographical-order](https://leetcode.com/problems/k-th-smallest-in-lexicographical-order)|||Hard|

|441|[arranging-coins](https://leetcode.com/problems/arranging-coins)|||Easy|

|442|[find-all-duplicates-in-an-array](https://leetcode.com/problems/find-all-duplicates-in-an-array)|||Medium|

|443|[string-compression](https://leetcode.com/problems/string-compression)||[:memo:](https://leetcode.com/articles/string-compression/)|Easy|

|444|[sequence-reconstruction](https://leetcode.com/problems/sequence-reconstruction)|:lock:||Medium|

|445|[add-two-numbers-ii](https://leetcode.com/problems/add-two-numbers-ii)|||Medium|

|446|[arithmetic-slices-ii-subsequence](https://leetcode.com/problems/arithmetic-slices-ii-subsequence)||[:memo:](https://leetcode.com/articles/arithmetic-slices-ii-subsequence/)|Hard|

|447|[number-of-boomerangs](https://leetcode.com/problems/number-of-boomerangs)|||Easy|

|448|[find-all-numbers-disappeared-in-an-array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array)|||Easy|

|449|[serialize-and-deserialize-bst](https://leetcode.com/problems/serialize-and-deserialize-bst)|||Medium|

|450|[delete-node-in-a-bst](https://leetcode.com/problems/delete-node-in-a-bst)|||Medium|

|451|[sort-characters-by-frequency](https://leetcode.com/problems/sort-characters-by-frequency)|||Medium|

|452|[minimum-number-of-arrows-to-burst-balloons](https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons)|||Medium|

|453|[minimum-moves-to-equal-array-elements](https://leetcode.com/problems/minimum-moves-to-equal-array-elements)||[:memo:](https://leetcode.com/articles/minimum-moves-to-equal-array-elements/)|Easy|

|454|[4sum-ii](https://leetcode.com/problems/4sum-ii)|||Medium|

|455|[assign-cookies](https://leetcode.com/problems/assign-cookies)|||Easy|

|456|[132-pattern](https://leetcode.com/problems/132-pattern)||[:memo:](https://leetcode.com/articles/132-pattern/)|Medium|

|457|[circular-array-loop](https://leetcode.com/problems/circular-array-loop)|||Medium|

|458|[poor-pigs](https://leetcode.com/problems/poor-pigs)|||Easy|

|459|[repeated-substring-pattern](https://leetcode.com/problems/repeated-substring-pattern)|||Easy|

|460|[lfu-cache](https://leetcode.com/problems/lfu-cache)|||Hard|

|461|[hamming-distance](https://leetcode.com/problems/hamming-distance)|||Easy|

|462|[minimum-moves-to-equal-array-elements-ii](https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii)||[:memo:](https://leetcode.com/articles/minimum-moves-to-equal-array-elements-ii/)|Medium|

|463|[island-perimeter](https://leetcode.com/problems/island-perimeter)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/463-island-perimeter/island-perimeter.cpp)||Easy|

|464|[can-i-win](https://leetcode.com/problems/can-i-win)|||Medium|

|465|[optimal-account-balancing](https://leetcode.com/problems/optimal-account-balancing)|:lock:||Hard|

|466|[count-the-repetitions](https://leetcode.com/problems/count-the-repetitions)||[:memo:](https://leetcode.com/articles/count-the-repetitions/)|Hard|

|467|[unique-substrings-in-wraparound-string](https://leetcode.com/problems/unique-substrings-in-wraparound-string)|||Medium|

|468|[validate-ip-address](https://leetcode.com/problems/validate-ip-address)|||Medium|

|469|[convex-polygon](https://leetcode.com/problems/convex-polygon)|:lock:||Medium|

|471|[encode-string-with-shortest-length](https://leetcode.com/problems/encode-string-with-shortest-length)|:lock:||Hard|

|472|[concatenated-words](https://leetcode.com/problems/concatenated-words)|||Hard|

|473|[matchsticks-to-square](https://leetcode.com/problems/matchsticks-to-square)|||Medium|

|474|[ones-and-zeroes](https://leetcode.com/problems/ones-and-zeroes)||[:memo:](https://leetcode.com/articles/ones-and-zeroes/)|Medium|

|475|[heaters](https://leetcode.com/problems/heaters)|||Easy|

|476|[number-complement](https://leetcode.com/problems/number-complement)|||Easy|

|477|[total-hamming-distance](https://leetcode.com/problems/total-hamming-distance)||[:memo:](https://leetcode.com/articles/total-hamming-distance/)|Medium|

|479|[largest-palindrome-product](https://leetcode.com/problems/largest-palindrome-product)|||Easy|

|480|[sliding-window-median](https://leetcode.com/problems/sliding-window-median)||[:memo:](https://leetcode.com/articles/sliding-window-median/)|Hard|

|481|[magical-string](https://leetcode.com/problems/magical-string)|||Medium|

|482|[license-key-formatting](https://leetcode.com/problems/license-key-formatting)|||Easy|

|483|[smallest-good-base](https://leetcode.com/problems/smallest-good-base)|||Hard|

|484|[find-permutation](https://leetcode.com/problems/find-permutation)|:lock:|[:memo:](https://leetcode.com/articles/find-permutation/)|Medium|

|485|[max-consecutive-ones](https://leetcode.com/problems/max-consecutive-ones)|||Easy|

|486|[predict-the-winner](https://leetcode.com/problems/predict-the-winner)||[:memo:](https://leetcode.com/articles/predict-the-winner/)|Medium|

|487|[max-consecutive-ones-ii](https://leetcode.com/problems/max-consecutive-ones-ii)|:lock:||Medium|

|488|[zuma-game](https://leetcode.com/problems/zuma-game)|||Hard|

|490|[the-maze](https://leetcode.com/problems/the-maze)|:lock:|[:memo:](https://leetcode.com/articles/the-maze/)|Medium|

|491|[increasing-subsequences](https://leetcode.com/problems/increasing-subsequences)|||Medium|

|492|[construct-the-rectangle](https://leetcode.com/problems/construct-the-rectangle)|||Easy|

|493|[reverse-pairs](https://leetcode.com/problems/reverse-pairs)||[:memo:](https://leetcode.com/articles/reverse-pairs/)|Hard|

|494|[target-sum](https://leetcode.com/problems/target-sum)||[:memo:](https://leetcode.com/articles/target-sum/)|Medium|

|495|[teemo-attacking](https://leetcode.com/problems/teemo-attacking)|||Medium|

|496|[next-greater-element-i](https://leetcode.com/problems/next-greater-element-i)||[:memo:](https://leetcode.com/articles/greater-element-i/)|Easy|

|498|[diagonal-traverse](https://leetcode.com/problems/diagonal-traverse)|||Medium|

|499|[the-maze-iii](https://leetcode.com/problems/the-maze-iii)|:lock:||Hard|

|500|[keyboard-row](https://leetcode.com/problems/keyboard-row)|||Easy|

|501|[find-mode-in-binary-search-tree](https://leetcode.com/problems/find-mode-in-binary-search-tree)|||Easy|

|502|[ipo](https://leetcode.com/problems/ipo)|||Hard|

|503|[next-greater-element-ii](https://leetcode.com/problems/next-greater-element-ii)||[:memo:](https://leetcode.com/articles/next-greater-element-ii/)|Medium|

|504|[base-7](https://leetcode.com/problems/base-7)|||Easy|

|505|[the-maze-ii](https://leetcode.com/problems/the-maze-ii)|:lock:|[:memo:](https://leetcode.com/articles/the-maze-ii/)|Medium|

|506|[relative-ranks](https://leetcode.com/problems/relative-ranks)|||Easy|

|507|[perfect-number](https://leetcode.com/problems/perfect-number)||[:memo:](https://leetcode.com/articles/perfect-number/)|Easy|

|508|[most-frequent-subtree-sum](https://leetcode.com/problems/most-frequent-subtree-sum)|||Medium|

|513|[find-bottom-left-tree-value](https://leetcode.com/problems/find-bottom-left-tree-value)|||Medium|

|514|[freedom-trail](https://leetcode.com/problems/freedom-trail)|||Hard|

|515|[find-largest-value-in-each-tree-row](https://leetcode.com/problems/find-largest-value-in-each-tree-row)|||Medium|

|516|[longest-palindromic-subsequence](https://leetcode.com/problems/longest-palindromic-subsequence)|||Medium|

|517|[super-washing-machines](https://leetcode.com/problems/super-washing-machines)|||Hard|

|518|[coin-change-2](https://leetcode.com/problems/coin-change-2)|||Medium|

|520|[detect-capital](https://leetcode.com/problems/detect-capital)|||Easy|

|521|[longest-uncommon-subsequence-i](https://leetcode.com/problems/longest-uncommon-subsequence-i)||[:memo:](https://leetcode.com/articles/longest-uncommon-subsequence-i/)|Easy|

|522|[longest-uncommon-subsequence-ii](https://leetcode.com/problems/longest-uncommon-subsequence-ii)||[:memo:](https://leetcode.com/articles/longest-uncommon-subsequence-ii/)|Medium|

|523|[continuous-subarray-sum](https://leetcode.com/problems/continuous-subarray-sum)||[:memo:](https://leetcode.com/articles/continous-subarray-sum/)|Medium|

|524|[longest-word-in-dictionary-through-deleting](https://leetcode.com/problems/longest-word-in-dictionary-through-deleting)||[:memo:](https://leetcode.com/articles/longest-word-in-dictionary-through-deletion/)|Medium|

|525|[contiguous-array](https://leetcode.com/problems/contiguous-array)||[:memo:](https://leetcode.com/articles/contiguous-array/)|Medium|

|526|[beautiful-arrangement](https://leetcode.com/problems/beautiful-arrangement)||[:memo:](https://leetcode.com/articles/beautiful-arrangement/)|Medium|

|527|[word-abbreviation](https://leetcode.com/problems/word-abbreviation)|:lock:|[:memo:](https://leetcode.com/articles/word-abbreviation/)|Hard|

|529|[minesweeper](https://leetcode.com/problems/minesweeper)|||Medium|

|530|[minimum-absolute-difference-in-bst](https://leetcode.com/problems/minimum-absolute-difference-in-bst)|||Easy|

|531|[lonely-pixel-i](https://leetcode.com/problems/lonely-pixel-i)|:lock:||Medium|

|532|[k-diff-pairs-in-an-array](https://leetcode.com/problems/k-diff-pairs-in-an-array)|||Easy|

|533|[lonely-pixel-ii](https://leetcode.com/problems/lonely-pixel-ii)|:lock:||Medium|

|535|[encode-and-decode-tinyurl](https://leetcode.com/problems/encode-and-decode-tinyurl)||[:memo:](https://leetcode.com/articles/encode-and-decode-tinyurl/)|Medium|

|536|[construct-binary-tree-from-string](https://leetcode.com/problems/construct-binary-tree-from-string)|:lock:||Medium|

|537|[complex-number-multiplication](https://leetcode.com/problems/complex-number-multiplication)||[:memo:](https://leetcode.com/articles/complex-number-multiplication/)|Medium|

|538|[convert-bst-to-greater-tree](https://leetcode.com/problems/convert-bst-to-greater-tree)||[:memo:](https://leetcode.com/articles/convert-bst-to-greater-tree/)|Easy|

|539|[minimum-time-difference](https://leetcode.com/problems/minimum-time-difference)|||Medium|

|540|[single-element-in-a-sorted-array](https://leetcode.com/problems/single-element-in-a-sorted-array)|||Medium|

|541|[reverse-string-ii](https://leetcode.com/problems/reverse-string-ii)||[:memo:](https://leetcode.com/articles/reverse-string-ii/)|Easy|

|542|[01-matrix](https://leetcode.com/problems/01-matrix)||[:memo:](https://leetcode.com/articles/01-matrix/)|Medium|

|543|[diameter-of-binary-tree](https://leetcode.com/problems/diameter-of-binary-tree)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/543-diameter-of-binary-tree/diameter-of-binary-tree.cpp)|[:memo:](https://leetcode.com/articles/diameter-of-binary-tree/)|Easy|

|544|[output-contest-matches](https://leetcode.com/problems/output-contest-matches)|:lock:|[:memo:](https://leetcode.com/articles/output-contest-matches/)|Medium|

|545|[boundary-of-binary-tree](https://leetcode.com/problems/boundary-of-binary-tree)|:lock:|[:memo:](https://leetcode.com/articles/boundary-of-binary-tree/)|Medium|

|546|[remove-boxes](https://leetcode.com/problems/remove-boxes)||[:memo:](https://leetcode.com/articles/remove-boxes/)|Hard|

|547|[friend-circles](https://leetcode.com/problems/friend-circles)||[:memo:](https://leetcode.com/articles/friend-circles/)|Medium|

|548|[split-array-with-equal-sum](https://leetcode.com/problems/split-array-with-equal-sum)|:lock:|[:memo:](https://leetcode.com/articles/split-array-with-equal-sum/)|Medium|

|549|[binary-tree-longest-consecutive-sequence-ii](https://leetcode.com/problems/binary-tree-longest-consecutive-sequence-ii)|:lock:|[:memo:](https://leetcode.com/articles/binary-tree-longest-consecutive-sequence-ii/)|Medium|

|551|[student-attendance-record-i](https://leetcode.com/problems/student-attendance-record-i)||[:memo:](https://leetcode.com/articles/student-attendance-record-i/)|Easy|

|552|[student-attendance-record-ii](https://leetcode.com/problems/student-attendance-record-ii)||[:memo:](https://leetcode.com/articles/student-attendance-record-ii/)|Hard|

|553|[optimal-division](https://leetcode.com/problems/optimal-division)||[:memo:](https://leetcode.com/articles/optimal-division/)|Medium|

|554|[brick-wall](https://leetcode.com/problems/brick-wall)||[:memo:](https://leetcode.com/articles/brick-wall/)|Medium|

|555|[split-concatenated-strings](https://leetcode.com/problems/split-concatenated-strings)|:lock:|[:memo:](https://leetcode.com/articles/split-assembled-strings/)|Medium|

|556|[next-greater-element-iii](https://leetcode.com/problems/next-greater-element-iii)||[:memo:](https://leetcode.com/articles/next-greater-element-iii/)|Medium|

|557|[reverse-words-in-a-string-iii](https://leetcode.com/problems/reverse-words-in-a-string-iii)||[:memo:](https://leetcode.com/articles/reverse-words-in-a-string/)|Easy|

|560|[subarray-sum-equals-k](https://leetcode.com/problems/subarray-sum-equals-k)||[:memo:](https://leetcode.com/articles/subarray-sum-equals-k/)|Medium|

|561|[array-partition-i](https://leetcode.com/problems/array-partition-i)||[:memo:](https://leetcode.com/articles/array-partitioning-i/)|Easy|

|562|[longest-line-of-consecutive-one-in-matrix](https://leetcode.com/problems/longest-line-of-consecutive-one-in-matrix)|:lock:|[:memo:](https://leetcode.com/articles/longest-line-of-consecutive-one-in-a-matrix/)|Medium|

|563|[binary-tree-tilt](https://leetcode.com/problems/binary-tree-tilt)||[:memo:](https://leetcode.com/articles/binary-tree-tilt/)|Easy|

|564|[find-the-closest-palindrome](https://leetcode.com/problems/find-the-closest-palindrome)||[:memo:](https://leetcode.com/articles/find-the-closest-palindrome/)|Hard|

|565|[array-nesting](https://leetcode.com/problems/array-nesting)||[:memo:](https://leetcode.com/articles/array-nesting/)|Medium|

|566|[reshape-the-matrix](https://leetcode.com/problems/reshape-the-matrix)||[:memo:](https://leetcode.com/articles/reshape-the-matrix/)|Easy|

|567|[permutation-in-string](https://leetcode.com/problems/permutation-in-string)||[:memo:](https://leetcode.com/articles/short-permutation-in-a-long-string/)|Medium|

|568|[maximum-vacation-days](https://leetcode.com/problems/maximum-vacation-days)|:lock:|[:memo:](https://leetcode.com/articles/maximum-vacation-days/)|Hard|

|572|[subtree-of-another-tree](https://leetcode.com/problems/subtree-of-another-tree)||[:memo:](https://leetcode.com/articles/subtree-of-another-tree/)|Easy|

|573|[squirrel-simulation](https://leetcode.com/problems/squirrel-simulation)|:lock:|[:memo:](https://leetcode.com/articles/squirrel-simulation/)|Medium|

|575|[distribute-candies](https://leetcode.com/problems/distribute-candies)||[:memo:](https://leetcode.com/articles/distribute-candies/)|Easy|

|576|[out-of-boundary-paths](https://leetcode.com/problems/out-of-boundary-paths)||[:memo:](https://leetcode.com/articles/out-of-boundary-paths/)|Medium|

|581|[shortest-unsorted-continuous-subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray)||[:memo:](https://leetcode.com/articles/shortest-unsorted-continous-subarray/)|Easy|

|582|[kill-process](https://leetcode.com/problems/kill-process)|:lock:|[:memo:](https://leetcode.com/articles/kill-process/)|Medium|

|583|[delete-operation-for-two-strings](https://leetcode.com/problems/delete-operation-for-two-strings)||[:memo:](https://leetcode.com/articles/delete-operation-for-two-strings/)|Medium|

|587|[erect-the-fence](https://leetcode.com/problems/erect-the-fence)||[:memo:](https://leetcode.com/articles/erect-the-fence/)|Hard|

|588|[design-in-memory-file-system](https://leetcode.com/problems/design-in-memory-file-system)|:lock:|[:memo:](https://leetcode.com/articles/design-in-memory-file-system/)|Hard|

|591|[tag-validator](https://leetcode.com/problems/tag-validator)||[:memo:](https://leetcode.com/articles/tag-validator/)|Hard|

|592|[fraction-addition-and-subtraction](https://leetcode.com/problems/fraction-addition-and-subtraction)||[:memo:](https://leetcode.com/articles/kill-process-3/)|Medium|

|593|[valid-square](https://leetcode.com/problems/valid-square)||[:memo:](https://leetcode.com/articles/valid-square/)|Medium|

|594|[longest-harmonious-subsequence](https://leetcode.com/problems/longest-harmonious-subsequence)||[:memo:](https://leetcode.com/articles/longest-harmonious-subsequence/)|Easy|

|598|[range-addition-ii](https://leetcode.com/problems/range-addition-ii)||[:memo:](https://leetcode.com/articles/range-addition-ii/)|Easy|

|599|[minimum-index-sum-of-two-lists](https://leetcode.com/problems/minimum-index-sum-of-two-lists)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/599-minimum-index-sum-of-two-lists/minimum-index-sum-of-two-lists.cpp)|[:memo:](https://leetcode.com/articles/minimum-index-sum-of-two-lists/)|Easy|

|600|[non-negative-integers-without-consecutive-ones](https://leetcode.com/problems/non-negative-integers-without-consecutive-ones)||[:memo:](https://leetcode.com/articles/non-negative-integers-without-consecutive-ones/)|Hard|

|604|[design-compressed-string-iterator](https://leetcode.com/problems/design-compressed-string-iterator)|:lock:|[:memo:](https://leetcode.com/articles/desing-compressed-string-iterator/)|Easy|

|605|[can-place-flowers](https://leetcode.com/problems/can-place-flowers)||[:memo:](https://leetcode.com/articles/can-place-flowers/)|Easy|

|606|[construct-string-from-binary-tree](https://leetcode.com/problems/construct-string-from-binary-tree)||[:memo:](https://leetcode.com/articles/construct-string-from-binary-tree/)|Easy|

|609|[find-duplicate-file-in-system](https://leetcode.com/problems/find-duplicate-file-in-system)||[:memo:](https://leetcode.com/articles/find-duplicate/)|Medium|

|611|[valid-triangle-number](https://leetcode.com/problems/valid-triangle-number)||[:memo:](https://leetcode.com/articles/valid-triangle-number/)|Medium|

|616|[add-bold-tag-in-string](https://leetcode.com/problems/add-bold-tag-in-string)|:lock:|[:memo:](https://leetcode.com/articles/add-bold-tag-in-a-string/)|Medium|

|617|[merge-two-binary-trees](https://leetcode.com/problems/merge-two-binary-trees)||[:memo:](https://leetcode.com/articles/merge-two-binary-trees/)|Easy|

|621|[task-scheduler](https://leetcode.com/problems/task-scheduler)||[:memo:](https://leetcode.com/articles/task-scheduler/)|Medium|

|623|[add-one-row-to-tree](https://leetcode.com/problems/add-one-row-to-tree)||[:memo:](https://leetcode.com/articles/add-one-row-in-a-tree/)|Medium|

|624|[maximum-distance-in-arrays](https://leetcode.com/problems/maximum-distance-in-arrays)|:lock:|[:memo:](https://leetcode.com/articles/maximum-distance-in-array/)|Easy|

|625|[minimum-factorization](https://leetcode.com/problems/minimum-factorization)|:lock:|[:memo:](https://leetcode.com/articles/minimum-factorization/)|Medium|

|628|[maximum-product-of-three-numbers](https://leetcode.com/problems/maximum-product-of-three-numbers)||[:memo:](https://leetcode.com/articles/maximmum-product-of-three-numbers/)|Easy|

|629|[k-inverse-pairs-array](https://leetcode.com/problems/k-inverse-pairs-array)||[:memo:](https://leetcode.com/articles/k-inverse-pairs-array/)|Hard|

|630|[course-schedule-iii](https://leetcode.com/problems/course-schedule-iii)||[:memo:](https://leetcode.com/articles/course-schedule-iii/)|Hard|

|631|[design-excel-sum-formula](https://leetcode.com/problems/design-excel-sum-formula)|:lock:|[:memo:](https://leetcode.com/articles/design-excel-sum-formula/)|Hard|

|632|[smallest-range](https://leetcode.com/problems/smallest-range)||[:memo:](https://leetcode.com/articles/smallest-range/)|Hard|

|633|[sum-of-square-numbers](https://leetcode.com/problems/sum-of-square-numbers)||[:memo:](https://leetcode.com/articles/sum-of-square-numbers/)|Easy|

|634|[find-the-derangement-of-an-array](https://leetcode.com/problems/find-the-derangement-of-an-array)|:lock:|[:memo:](https://leetcode.com/articles/find-derangements/)|Medium|

|635|[design-log-storage-system](https://leetcode.com/problems/design-log-storage-system)|:lock:|[:memo:](https://leetcode.com/articles/design-log-storage/)|Medium|

|636|[exclusive-time-of-functions](https://leetcode.com/problems/exclusive-time-of-functions)||[:memo:](https://leetcode.com/articles/exclusive-time-of-functions/)|Medium|

|637|[average-of-levels-in-binary-tree](https://leetcode.com/problems/average-of-levels-in-binary-tree)||[:memo:](https://leetcode.com/articles/average-of-levels/)|Easy|

|638|[shopping-offers](https://leetcode.com/problems/shopping-offers)||[:memo:](https://leetcode.com/articles/shopping-offers/)|Medium|

|639|[decode-ways-ii](https://leetcode.com/problems/decode-ways-ii)||[:memo:](https://leetcode.com/articles/decode-ways-ii/)|Hard|

|640|[solve-the-equation](https://leetcode.com/problems/solve-the-equation)||[:memo:](https://leetcode.com/articles/solve-the-equation/)|Medium|

|642|[design-search-autocomplete-system](https://leetcode.com/problems/design-search-autocomplete-system)|:lock:|[:memo:](https://leetcode.com/articles/design-search-autocomplete-system/)|Hard|

|643|[maximum-average-subarray-i](https://leetcode.com/problems/maximum-average-subarray-i)||[:memo:](https://leetcode.com/articles/maximum-average-subarray/)|Easy|

|644|[maximum-average-subarray-ii](https://leetcode.com/problems/maximum-average-subarray-ii)|:lock:|[:memo:](https://leetcode.com/articles/maximum-average-subarray-ii/)|Hard|

|645|[set-mismatch](https://leetcode.com/problems/set-mismatch)||[:memo:](https://leetcode.com/articles/set-mismatch/)|Easy|

|646|[maximum-length-of-pair-chain](https://leetcode.com/problems/maximum-length-of-pair-chain)||[:memo:](https://leetcode.com/articles/maximum-length-of-pair-chain/)|Medium|

|647|[palindromic-substrings](https://leetcode.com/problems/palindromic-substrings)||[:memo:](https://leetcode.com/articles/palindromic-substrings/)|Medium|

|648|[replace-words](https://leetcode.com/problems/replace-words)||[:memo:](https://leetcode.com/articles/replace-words/)|Medium|

|649|[dota2-senate](https://leetcode.com/problems/dota2-senate)||[:memo:](https://leetcode.com/articles/dota2-senate/)|Medium|

|650|[2-keys-keyboard](https://leetcode.com/problems/2-keys-keyboard)||[:memo:](https://leetcode.com/articles/2-keys-keyboard/)|Medium|

|651|[4-keys-keyboard](https://leetcode.com/problems/4-keys-keyboard)|:lock:|[:memo:](https://leetcode.com/articles/4-keys-keyboard/)|Medium|

|652|[find-duplicate-subtrees](https://leetcode.com/problems/find-duplicate-subtrees)||[:memo:](https://leetcode.com/articles/find-duplicate-subtrees/)|Medium|

|653|[two-sum-iv-input-is-a-bst](https://leetcode.com/problems/two-sum-iv-input-is-a-bst)||[:memo:](https://leetcode.com/articles/two-sum-iv/)|Easy|

|654|[maximum-binary-tree](https://leetcode.com/problems/maximum-binary-tree)||[:memo:](https://leetcode.com/articles/maximum-binary-tree/)|Medium|

|655|[print-binary-tree](https://leetcode.com/problems/print-binary-tree)||[:memo:](https://leetcode.com/articles/print-binary-tree/)|Medium|

|656|[coin-path](https://leetcode.com/problems/coin-path)|:lock:|[:memo:](https://leetcode.com/articles/coin-path/)|Hard|

|657|[judge-route-circle](https://leetcode.com/problems/judge-route-circle)||[:memo:](https://leetcode.com/articles/judge-route-circle/)|Easy|

|658|[find-k-closest-elements](https://leetcode.com/problems/find-k-closest-elements)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/658-find-k-closest-elements/find-k-closest-elements.cpp)|[:memo:](https://leetcode.com/articles/find-k-closest-elements/)|Medium|

|659|[split-array-into-consecutive-subsequences](https://leetcode.com/problems/split-array-into-consecutive-subsequences)||[:memo:](https://leetcode.com/articles/split-array-into-consecutive-subsequences/)|Medium|

|660|[remove-9](https://leetcode.com/problems/remove-9)|:lock:|[:memo:](https://leetcode.com/articles/remove-9/)|Hard|

|661|[image-smoother](https://leetcode.com/problems/image-smoother)||[:memo:](https://leetcode.com/articles/image-smoother/)|Easy|

|662|[maximum-width-of-binary-tree](https://leetcode.com/problems/maximum-width-of-binary-tree)||[:memo:](https://leetcode.com/articles/maximum-width-of-binary-tree/)|Medium|

|663|[equal-tree-partition](https://leetcode.com/problems/equal-tree-partition)|:lock:|[:memo:](https://leetcode.com/articles/equal-tree-partition/)|Medium|

|664|[strange-printer](https://leetcode.com/problems/strange-printer)||[:memo:](https://leetcode.com/articles/strange-printer/)|Hard|

|665|[non-decreasing-array](https://leetcode.com/problems/non-decreasing-array)||[:memo:](https://leetcode.com/articles/non-decreasing-array/)|Easy|

|666|[path-sum-iv](https://leetcode.com/problems/path-sum-iv)|:lock:|[:memo:](https://leetcode.com/articles/path-sum-iv/)|Medium|

|667|[beautiful-arrangement-ii](https://leetcode.com/problems/beautiful-arrangement-ii)||[:memo:](https://leetcode.com/articles/beautiful-arrangement-ii/)|Medium|

|668|[kth-smallest-number-in-multiplication-table](https://leetcode.com/problems/kth-smallest-number-in-multiplication-table)||[:memo:](https://leetcode.com/articles/kth-smallest-number-in-multiplication-table/)|Hard|

|669|[trim-a-binary-search-tree](https://leetcode.com/problems/trim-a-binary-search-tree)||[:memo:](https://leetcode.com/articles/trim-a-binary-search-tree/)|Easy|

|670|[maximum-swap](https://leetcode.com/problems/maximum-swap)||[:memo:](https://leetcode.com/articles/maximum-swap/)|Medium|

|671|[second-minimum-node-in-a-binary-tree](https://leetcode.com/problems/second-minimum-node-in-a-binary-tree)||[:memo:](https://leetcode.com/articles/second-minimum-node-in-a-binary-tree/)|Easy|

|672|[bulb-switcher-ii](https://leetcode.com/problems/bulb-switcher-ii)||[:memo:](https://leetcode.com/articles/bulb-switcher-ii/)|Medium|

|673|[number-of-longest-increasing-subsequence](https://leetcode.com/problems/number-of-longest-increasing-subsequence)||[:memo:](https://leetcode.com/articles/number-of-longest-increasing-subsequence/)|Medium|

|674|[longest-continuous-increasing-subsequence](https://leetcode.com/problems/longest-continuous-increasing-subsequence)||[:memo:](https://leetcode.com/articles/longest-continuous-increasing-subsequence/)|Easy|

|675|[cut-off-trees-for-golf-event](https://leetcode.com/problems/cut-off-trees-for-golf-event)||[:memo:](https://leetcode.com/articles/cutoff-trees-for-golf-event/)|Hard|

|676|[implement-magic-dictionary](https://leetcode.com/problems/implement-magic-dictionary)||[:memo:](https://leetcode.com/articles/implement-magic-dictionary/)|Medium|

|677|[map-sum-pairs](https://leetcode.com/problems/map-sum-pairs)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/677-map-sum-pairs/map-sum-pairs.cpp)|[:memo:](https://leetcode.com/articles/map-sum-pairs/)|Medium|

|678|[valid-parenthesis-string](https://leetcode.com/problems/valid-parenthesis-string)||[:memo:](https://leetcode.com/articles/valid-parenthesis-string/)|Medium|

|679|[24-game](https://leetcode.com/problems/24-game)||[:memo:](https://leetcode.com/articles/24-game/)|Hard|

|680|[valid-palindrome-ii](https://leetcode.com/problems/valid-palindrome-ii)||[:memo:](https://leetcode.com/articles/valid-palindrome-ii/)|Easy|

|681|[next-closest-time](https://leetcode.com/problems/next-closest-time)|:lock:|[:memo:](https://leetcode.com/articles/next-closest-time/)|Medium|

|682|[baseball-game](https://leetcode.com/problems/baseball-game)||[:memo:](https://leetcode.com/articles/baseball-game/)|Easy|

|683|[k-empty-slots](https://leetcode.com/problems/k-empty-slots)|:lock:|[:memo:](https://leetcode.com/articles/k-empty-slots/)|Hard|

|684|[redundant-connection](https://leetcode.com/problems/redundant-connection)||[:memo:](https://leetcode.com/articles/redundant-connection/)|Medium|

|685|[redundant-connection-ii](https://leetcode.com/problems/redundant-connection-ii)||[:memo:](https://leetcode.com/articles/redundant-connection-ii/)|Hard|

|686|[repeated-string-match](https://leetcode.com/problems/repeated-string-match)||[:memo:](https://leetcode.com/articles/repeated-string-match/)|Easy|

|687|[longest-univalue-path](https://leetcode.com/problems/longest-univalue-path)||[:memo:](https://leetcode.com/articles/longest-univalue-path/)|Easy|

|688|[knight-probability-in-chessboard](https://leetcode.com/problems/knight-probability-in-chessboard)||[:memo:](https://leetcode.com/articles/knight-probability-in-chessboard/)|Medium|

|689|[maximum-sum-of-3-non-overlapping-subarrays](https://leetcode.com/problems/maximum-sum-of-3-non-overlapping-subarrays)||[:memo:](https://leetcode.com/articles/maximum-sum-of-3-non-overlapping-intervals/)|Hard|

|690|[employee-importance](https://leetcode.com/problems/employee-importance)||[:memo:](https://leetcode.com/articles/employee-importance/)|Easy|

|691|[stickers-to-spell-word](https://leetcode.com/problems/stickers-to-spell-word)||[:memo:](https://leetcode.com/articles/stickers-to-spell-word/)|Hard|

|692|[top-k-frequent-words](https://leetcode.com/problems/top-k-frequent-words)||[:memo:](https://leetcode.com/articles/top-k-frequent-words/)|Medium|

|693|[binary-number-with-alternating-bits](https://leetcode.com/problems/binary-number-with-alternating-bits)||[:memo:](https://leetcode.com/articles/binary-number-with-alternating-bits/)|Easy|

|694|[number-of-distinct-islands](https://leetcode.com/problems/number-of-distinct-islands)|:lock:|[:memo:](https://leetcode.com/articles/number-of-distinct-islands/)|Medium|

|695|[max-area-of-island](https://leetcode.com/problems/max-area-of-island)||[:memo:](https://leetcode.com/articles/max-area-of-island/)|Easy|

|696|[count-binary-substrings](https://leetcode.com/problems/count-binary-substrings)||[:memo:](https://leetcode.com/articles/count-binary-substrings/)|Easy|

|697|[degree-of-an-array](https://leetcode.com/problems/degree-of-an-array)||[:memo:](https://leetcode.com/articles/degree-of-an-array/)|Easy|

|698|[partition-to-k-equal-sum-subsets](https://leetcode.com/problems/partition-to-k-equal-sum-subsets)||[:memo:](https://leetcode.com/articles/partition-to-k-equal-sum-subsets/)|Medium|

|699|[falling-squares](https://leetcode.com/problems/falling-squares)||[:memo:](https://leetcode.com/articles/falling-squares/)|Hard|

|711|[number-of-distinct-islands-ii](https://leetcode.com/problems/number-of-distinct-islands-ii)|:lock:|[:memo:](https://leetcode.com/articles/number-of-distinct-islands-ii/)|Hard|

|712|[minimum-ascii-delete-sum-for-two-strings](https://leetcode.com/problems/minimum-ascii-delete-sum-for-two-strings)||[:memo:](https://leetcode.com/articles/minimum-ascii-delete-sum-for-two-strings/)|Medium|

|713|[subarray-product-less-than-k](https://leetcode.com/problems/subarray-product-less-than-k)||[:memo:](https://leetcode.com/articles/subarray-product-less-than-k/)|Medium|

|714|[best-time-to-buy-and-sell-stock-with-transaction-fee](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-transaction-fee)||[:memo:](https://leetcode.com/articles/best-time-to-buy-and-sell-stock-with-transaction-fee/)|Medium|

|715|[range-module](https://leetcode.com/problems/range-module)||[:memo:](https://leetcode.com/articles/range-module/)|Hard|

|716|[max-stack](https://leetcode.com/problems/max-stack)|:lock:|[:memo:](https://leetcode.com/articles/max-stack/)|Hard|

|717|[1-bit-and-2-bit-characters](https://leetcode.com/problems/1-bit-and-2-bit-characters)||[:memo:](https://leetcode.com/articles/1-bit-and-2-bit-characters/)|Easy|

|718|[maximum-length-of-repeated-subarray](https://leetcode.com/problems/maximum-length-of-repeated-subarray)||[:memo:](https://leetcode.com/articles/maximum-length-of-repeated-subarray/)|Medium|

|719|[find-k-th-smallest-pair-distance](https://leetcode.com/problems/find-k-th-smallest-pair-distance)||[:memo:](https://leetcode.com/articles/find-k-th-smallest-pair-distance/)|Hard|

|720|[longest-word-in-dictionary](https://leetcode.com/problems/longest-word-in-dictionary)||[:memo:](https://leetcode.com/articles/longest-word-in-dictionary/)|Easy|

|721|[accounts-merge](https://leetcode.com/problems/accounts-merge)||[:memo:](https://leetcode.com/articles/accounts-merge/)|Medium|

|722|[remove-comments](https://leetcode.com/problems/remove-comments)||[:memo:](https://leetcode.com/articles/remove-comments/)|Medium|

|723|[candy-crush](https://leetcode.com/problems/candy-crush)|:lock:|[:memo:](https://leetcode.com/articles/candy-crush/)|Medium|

|724|[find-pivot-index](https://leetcode.com/problems/find-pivot-index)||[:memo:](https://leetcode.com/articles/find-pivot-index/)|Easy|

|725|[split-linked-list-in-parts](https://leetcode.com/problems/split-linked-list-in-parts)||[:memo:](https://leetcode.com/articles/split-linked-list-in-parts/)|Medium|

|726|[number-of-atoms](https://leetcode.com/problems/number-of-atoms)||[:memo:](https://leetcode.com/articles/number-of-atoms/)|Hard|

|727|[minimum-window-subsequence](https://leetcode.com/problems/minimum-window-subsequence)|:lock:|[:memo:](https://leetcode.com/articles/minimum-window-subsequence/)|Hard|

|728|[self-dividing-numbers](https://leetcode.com/problems/self-dividing-numbers)||[:memo:](https://leetcode.com/articles/self-dividing-numbers/)|Easy|

|729|[my-calendar-i](https://leetcode.com/problems/my-calendar-i)||[:memo:](https://leetcode.com/articles/my-calendar-i/)|Medium|

|730|[count-different-palindromic-subsequences](https://leetcode.com/problems/count-different-palindromic-subsequences)||[:memo:](https://leetcode.com/articles/count-different-palindromic-subsequences/)|Hard|

|731|[my-calendar-ii](https://leetcode.com/problems/my-calendar-ii)||[:memo:](https://leetcode.com/articles/my-calendar-ii/)|Medium|

|732|[my-calendar-iii](https://leetcode.com/problems/my-calendar-iii)||[:memo:](https://leetcode.com/articles/my-calendar-iii/)|Hard|

|733|[flood-fill](https://leetcode.com/problems/flood-fill)||[:memo:](https://leetcode.com/articles/flood-fill/)|Easy|

|734|[sentence-similarity](https://leetcode.com/problems/sentence-similarity)|:lock:|[:memo:](https://leetcode.com/articles/sentence-similarity/)|Easy|

|735|[asteroid-collision](https://leetcode.com/problems/asteroid-collision)||[:memo:](https://leetcode.com/articles/asteroid-collision/)|Medium|

|736|[parse-lisp-expression](https://leetcode.com/problems/parse-lisp-expression)||[:memo:](https://leetcode.com/articles/parse-lisp-expression/)|Hard|

|737|[sentence-similarity-ii](https://leetcode.com/problems/sentence-similarity-ii)|:lock:|[:memo:](https://leetcode.com/articles/sentence-similarity-ii/)|Medium|

|738|[monotone-increasing-digits](https://leetcode.com/problems/monotone-increasing-digits)||[:memo:](https://leetcode.com/articles/monotone-increasing-digits/)|Medium|

|739|[daily-temperatures](https://leetcode.com/problems/daily-temperatures)||[:memo:](https://leetcode.com/articles/daily-temperatures/)|Medium|

|740|[delete-and-earn](https://leetcode.com/problems/delete-and-earn)||[:memo:](https://leetcode.com/articles/delete-and-earn/)|Medium|

|741|[cherry-pickup](https://leetcode.com/problems/cherry-pickup)||[:memo:](https://leetcode.com/articles/cherry-pickup/)|Hard|

|742|[to-lower-case](https://leetcode.com/problems/to-lower-case)|||Easy|

|743|[closest-leaf-in-a-binary-tree](https://leetcode.com/problems/closest-leaf-in-a-binary-tree)|:lock:|[:memo:](https://leetcode.com/articles/closest-leaf-in-binary-tree/)|Medium|

|744|[network-delay-time](https://leetcode.com/problems/network-delay-time)||[:memo:](https://leetcode.com/articles/network-delay-time/)|Medium|

|745|[find-smallest-letter-greater-than-target](https://leetcode.com/problems/find-smallest-letter-greater-than-target)||[:memo:](https://leetcode.com/articles/find-smallest-letter-greater-than-target/)|Easy|

|746|[prefix-and-suffix-search](https://leetcode.com/problems/prefix-and-suffix-search)||[:memo:](https://leetcode.com/articles/prefix-and-suffix-search/)|Hard|

|747|[min-cost-climbing-stairs](https://leetcode.com/problems/min-cost-climbing-stairs)||[:memo:](https://leetcode.com/articles/min-cost-climbing-stairs/)|Easy|

|748|[largest-number-at-least-twice-of-others](https://leetcode.com/problems/largest-number-at-least-twice-of-others)||[:memo:](https://leetcode.com/articles/largest-number-at-least-twice-of-others/)|Easy|

|749|[shortest-completing-word](https://leetcode.com/problems/shortest-completing-word)||[:memo:](https://leetcode.com/articles/shortest-completing-word/)|Medium|

|750|[contain-virus](https://leetcode.com/problems/contain-virus)||[:memo:](https://leetcode.com/articles/contain-virus/)|Hard|

|751|[number-of-corner-rectangles](https://leetcode.com/problems/number-of-corner-rectangles)|:lock:|[:memo:](https://leetcode.com/articles/number-of-corner-rectangles/)|Medium|

|752|[ip-to-cidr](https://leetcode.com/problems/ip-to-cidr)|:lock:|[:memo:](https://leetcode.com/articles/ip-to-cidr/)|Easy|

|753|[open-the-lock](https://leetcode.com/problems/open-the-lock)||[:memo:](https://leetcode.com/articles/open-the-lock/)|Medium|

|754|[cracking-the-safe](https://leetcode.com/problems/cracking-the-safe)||[:memo:](https://leetcode.com/articles/cracking-the-safe/)|Hard|

|755|[reach-a-number](https://leetcode.com/problems/reach-a-number)||[:memo:](https://leetcode.com/articles/reach-a-number/)|Medium|

|756|[pour-water](https://leetcode.com/problems/pour-water)|:lock:|[:memo:](https://leetcode.com/articles/pour-water/)|Medium|

|757|[pyramid-transition-matrix](https://leetcode.com/problems/pyramid-transition-matrix)||[:memo:](https://leetcode.com/articles/pyramid-transition-matrix/)|Medium|

|758|[convert-binary-search-tree-to-sorted-doubly-linked-list](https://leetcode.com/problems/convert-binary-search-tree-to-sorted-doubly-linked-list)|:lock:||Medium|

|759|[set-intersection-size-at-least-two](https://leetcode.com/problems/set-intersection-size-at-least-two)||[:memo:](https://leetcode.com/articles/set-intersection-size-at-least-two/)|Hard|

|760|[bold-words-in-string](https://leetcode.com/problems/bold-words-in-string)|:lock:|[:memo:](https://leetcode.com/articles/bold-words-in-string/)|Easy|

|761|[employee-free-time](https://leetcode.com/problems/employee-free-time)|:lock:|[:memo:](https://leetcode.com/articles/employee-free-time/)|Hard|

|762|[find-anagram-mappings](https://leetcode.com/problems/find-anagram-mappings)|:lock:|[:memo:](https://leetcode.com/articles/find-anagram-mappings/)|Easy|

|763|[special-binary-string](https://leetcode.com/problems/special-binary-string)||[:memo:](https://leetcode.com/articles/special-binary-string/)|Hard|

|764|[n-ary-tree-level-order-traversal](https://leetcode.com/problems/n-ary-tree-level-order-traversal)|||Easy|

|765|[serialize-and-deserialize-n-ary-tree](https://leetcode.com/problems/serialize-and-deserialize-n-ary-tree)|:lock:||Hard|

|766|[flatten-a-multilevel-doubly-linked-list](https://leetcode.com/problems/flatten-a-multilevel-doubly-linked-list)|||Medium|

|767|[prime-number-of-set-bits-in-binary-representation](https://leetcode.com/problems/prime-number-of-set-bits-in-binary-representation)||[:memo:](https://leetcode.com/articles/prime-number-of-set-bits-in-binary-representation/)|Easy|

|768|[partition-labels](https://leetcode.com/problems/partition-labels)||[:memo:](https://leetcode.com/articles/partition-labels/)|Medium|

|769|[largest-plus-sign](https://leetcode.com/problems/largest-plus-sign)||[:memo:](https://leetcode.com/articles/largest-plus-sign/)|Medium|

|770|[couples-holding-hands](https://leetcode.com/problems/couples-holding-hands)||[:memo:](https://leetcode.com/articles/couples-holding-hands/)|Hard|

|771|[encode-n-ary-tree-to-binary-tree](https://leetcode.com/problems/encode-n-ary-tree-to-binary-tree)|:lock:||Hard|

|772|[construct-quad-tree](https://leetcode.com/problems/construct-quad-tree)|||Easy|

|773|[quad-tree-intersection](https://leetcode.com/problems/quad-tree-intersection)|||Easy|

|774|[maximum-depth-of-n-ary-tree](https://leetcode.com/problems/maximum-depth-of-n-ary-tree)|||Easy|

|775|[n-ary-tree-preorder-traversal](https://leetcode.com/problems/n-ary-tree-preorder-traversal)|||Easy|

|776|[n-ary-tree-postorder-traversal](https://leetcode.com/problems/n-ary-tree-postorder-traversal)|||Easy|

|777|[toeplitz-matrix](https://leetcode.com/problems/toeplitz-matrix)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/777-toeplitz-matrix/toeplitz-matrix.cpp)|[:memo:](https://leetcode.com/articles/toeplitz-matrix/)|Easy|

|778|[reorganize-string](https://leetcode.com/problems/reorganize-string)||[:memo:](https://leetcode.com/articles/reorganized-string/)|Medium|

|779|[max-chunks-to-make-sorted-ii](https://leetcode.com/problems/max-chunks-to-make-sorted-ii)||[:memo:](https://leetcode.com/articles/max-chunks-to-make-sorted-ii/)|Hard|

|780|[max-chunks-to-make-sorted](https://leetcode.com/problems/max-chunks-to-make-sorted)||[:memo:](https://leetcode.com/articles/max-chunks-to-make-sorted-i/)|Medium|

|781|[basic-calculator-iv](https://leetcode.com/problems/basic-calculator-iv)||[:memo:](https://leetcode.com/articles/basic-calculator-iv/)|Hard|

|782|[jewels-and-stones](https://leetcode.com/problems/jewels-and-stones)||[:memo:](https://leetcode.com/articles/jewels-and-stones/)|Easy|

|783|[search-in-a-binary-search-tree](https://leetcode.com/problems/search-in-a-binary-search-tree)|||Easy|

|784|[insert-into-a-binary-search-tree](https://leetcode.com/problems/insert-into-a-binary-search-tree)|||Medium|

|785|[basic-calculator-iii](https://leetcode.com/problems/basic-calculator-iii)|:lock:||Hard|

|786|[search-in-a-sorted-array-of-unknown-size](https://leetcode.com/problems/search-in-a-sorted-array-of-unknown-size)|:lock:||Medium|

|787|[sliding-puzzle](https://leetcode.com/problems/sliding-puzzle)||[:memo:](https://leetcode.com/articles/sliding-puzzle/)|Hard|

|788|[minimize-max-distance-to-gas-station](https://leetcode.com/problems/minimize-max-distance-to-gas-station)|:lock:|[:memo:](https://leetcode.com/articles/minimize-max-distance-to-gas-station/)|Hard|

|789|[kth-largest-element-in-a-stream](https://leetcode.com/problems/kth-largest-element-in-a-stream)|||Easy|

|790|[global-and-local-inversions](https://leetcode.com/problems/global-and-local-inversions)||[:memo:](https://leetcode.com/articles/global-and-local-inversions/)|Medium|

|791|[split-bst](https://leetcode.com/problems/split-bst)|:lock:|[:memo:](https://leetcode.com/articles/split-bst/)|Medium|

|792|[binary-search](https://leetcode.com/problems/binary-search)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/792-binary-search/binary-search.cpp)||Easy|

|793|[swap-adjacent-in-lr-string](https://leetcode.com/problems/swap-adjacent-in-lr-string)||[:memo:](https://leetcode.com/articles/swap-adjacent-in-lr-string/)|Medium|

|794|[swim-in-rising-water](https://leetcode.com/problems/swim-in-rising-water)||[:memo:](https://leetcode.com/articles/swim-in-rising-water/)|Hard|

|795|[k-th-symbol-in-grammar](https://leetcode.com/problems/k-th-symbol-in-grammar)||[:memo:](https://leetcode.com/articles/k-th-symbol-in-grammar/)|Medium|

|796|[reaching-points](https://leetcode.com/problems/reaching-points)||[:memo:](https://leetcode.com/articles/reaching-points/)|Hard|

|797|[rabbits-in-forest](https://leetcode.com/problems/rabbits-in-forest)||[:memo:](https://leetcode.com/articles/rabbits-in-forest/)|Medium|

|798|[transform-to-chessboard](https://leetcode.com/problems/transform-to-chessboard)||[:memo:](https://leetcode.com/articles/transform-to-chessboard/)|Hard|

|799|[minimum-distance-between-bst-nodes](https://leetcode.com/problems/minimum-distance-between-bst-nodes)||[:memo:](https://leetcode.com/articles/minimum-distance-between-bst-nodes/)|Easy|

|800|[letter-case-permutation](https://leetcode.com/problems/letter-case-permutation)||[:memo:](https://leetcode.com/articles/letter-case-permutation/)|Easy|

|801|[is-graph-bipartite](https://leetcode.com/problems/is-graph-bipartite)||[:memo:](https://leetcode.com/articles/is-graph-bipartite/)|Medium|

|802|[k-th-smallest-prime-fraction](https://leetcode.com/problems/k-th-smallest-prime-fraction)||[:memo:](https://leetcode.com/articles/k-th-smallest-prime-fraction/)|Hard|

|803|[cheapest-flights-within-k-stops](https://leetcode.com/problems/cheapest-flights-within-k-stops)||[:memo:](https://leetcode.com/articles/cheapest-flights-within-k-stops/)|Medium|

|804|[rotated-digits](https://leetcode.com/problems/rotated-digits)||[:memo:](https://leetcode.com/articles/rotated-digits/)|Easy|

|805|[escape-the-ghosts](https://leetcode.com/problems/escape-the-ghosts)||[:memo:](https://leetcode.com/articles/escape-the-ghosts/)|Medium|

|806|[domino-and-tromino-tiling](https://leetcode.com/problems/domino-and-tromino-tiling)||[:memo:](https://leetcode.com/articles/domino-and-tromino-tiling/)|Medium|

|807|[custom-sort-string](https://leetcode.com/problems/custom-sort-string)||[:memo:](https://leetcode.com/articles/custom-sort-string/)|Medium|

|808|[number-of-matching-subsequences](https://leetcode.com/problems/number-of-matching-subsequences)||[:memo:](https://leetcode.com/articles/number-of-matching-subsequences/)|Medium|

|809|[preimage-size-of-factorial-zeroes-function](https://leetcode.com/problems/preimage-size-of-factorial-zeroes-function)||[:memo:](https://leetcode.com/articles/preimage-size-of-factorial-zeroes-function/)|Hard|

|810|[valid-tic-tac-toe-state](https://leetcode.com/problems/valid-tic-tac-toe-state)||[:memo:](https://leetcode.com/articles/valid-tic-tac-toe-state/)|Medium|

|811|[number-of-subarrays-with-bounded-maximum](https://leetcode.com/problems/number-of-subarrays-with-bounded-maximum)||[:memo:](https://leetcode.com/articles/number-of-subarrays-with-bounded-maximum/)|Medium|

|812|[rotate-string](https://leetcode.com/problems/rotate-string)||[:memo:](https://leetcode.com/articles/rotate-string/)|Easy|

|813|[all-paths-from-source-to-target](https://leetcode.com/problems/all-paths-from-source-to-target)||[:memo:](https://leetcode.com/articles/all-paths-from-source-to-target/)|Medium|

|814|[smallest-rotation-with-highest-score](https://leetcode.com/problems/smallest-rotation-with-highest-score)||[:memo:](https://leetcode.com/articles/smallest-rotation-with-highest-score/)|Hard|

|815|[champagne-tower](https://leetcode.com/problems/champagne-tower)||[:memo:](https://leetcode.com/articles/champagne-tower/)|Medium|

|816|[design-hashset](https://leetcode.com/problems/design-hashset)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/816-design-hashset/design-hashset.cpp)||Easy|

|817|[design-hashmap](https://leetcode.com/problems/design-hashmap)|[Cpp](https://github.com/fancymax/Leetcode_Swift/blob/master/817-design-hashmap/design-hashmap.cpp)||Easy|

|818|[similar-rgb-color](https://leetcode.com/problems/similar-rgb-color)|:lock:|[:memo:](https://leetcode.com/articles/similar-rgb-color/)|Easy|

|819|[minimum-swaps-to-make-sequences-increasing](https://leetcode.com/problems/minimum-swaps-to-make-sequences-increasing)||[:memo:](https://leetcode.com/articles/minimum-swaps-to-make-sequences-increasing/)|Medium|

|820|[find-eventual-safe-states](https://leetcode.com/problems/find-eventual-safe-states)||[:memo:](https://leetcode.com/articles/find-eventual-safe-states/)|Medium|

|821|[bricks-falling-when-hit](https://leetcode.com/problems/bricks-falling-when-hit)||[:memo:](https://leetcode.com/articles/bricks-falling-when-hit/)|Hard|

|822|[unique-morse-code-words](https://leetcode.com/problems/unique-morse-code-words)||[:memo:](https://leetcode.com/articles/unique-morse-code-words/)|Easy|

|823|[split-array-with-same-average](https://leetcode.com/problems/split-array-with-same-average)||[:memo:](https://leetcode.com/articles/split-array-with-same-average/)|Hard|

|824|[number-of-lines-to-write-string](https://leetcode.com/problems/number-of-lines-to-write-string)||[:memo:](https://leetcode.com/articles/number-of-lines-to-write-string/)|Easy|

|825|[max-increase-to-keep-city-skyline](https://leetcode.com/problems/max-increase-to-keep-city-skyline)||[:memo:](https://leetcode.com/articles/max-increase-to-keep-city-skyline/)|Medium|

|826|[soup-servings](https://leetcode.com/problems/soup-servings)||[:memo:](https://leetcode.com/articles/soup-servings/)|Medium|

|827|[expressive-words](https://leetcode.com/problems/expressive-words)||[:memo:](https://leetcode.com/articles/expressive-words/)|Medium|

|828|[chalkboard-xor-game](https://leetcode.com/problems/chalkboard-xor-game)||[:memo:](https://leetcode.com/articles/chalkboard-xor-game/)|Hard|

|829|[subdomain-visit-count](https://leetcode.com/problems/subdomain-visit-count)||[:memo:](https://leetcode.com/articles/subdomain-visit-count/)|Easy|

|830|[largest-triangle-area](https://leetcode.com/problems/largest-triangle-area)||[:memo:](https://leetcode.com/articles/largest-triangle-area/)|Easy|

|831|[largest-sum-of-averages](https://leetcode.com/problems/largest-sum-of-averages)||[:memo:](https://leetcode.com/articles/largest-sum-of-averages/)|Medium|

|832|[binary-tree-pruning](https://leetcode.com/problems/binary-tree-pruning)||[:memo:](https://leetcode.com/articles/binary-tree-pruning/)|Medium|

|833|[bus-routes](https://leetcode.com/problems/bus-routes)||[:memo:](https://leetcode.com/articles/bus-routes/)|Hard|

|834|[ambiguous-coordinates](https://leetcode.com/problems/ambiguous-coordinates)||[:memo:](https://leetcode.com/articles/ambiguous-coordinates/)|Medium|

|835|[linked-list-components](https://leetcode.com/problems/linked-list-components)||[:memo:](https://leetcode.com/articles/linked-list-components/)|Medium|

|836|[race-car](https://leetcode.com/problems/race-car)||[:memo:](https://leetcode.com/articles/race-car/)|Hard|

|837|[most-common-word](https://leetcode.com/problems/most-common-word)||[:memo:](https://leetcode.com/articles/most-common-word/)|Easy|

|838|[design-linked-list](https://leetcode.com/problems/design-linked-list)|||Easy|

|839|[short-encoding-of-words](https://leetcode.com/problems/short-encoding-of-words)||[:memo:](https://leetcode.com/articles/short-encoding-of-words/)|Medium|

|841|[shortest-distance-to-a-character](https://leetcode.com/problems/shortest-distance-to-a-character)||[:memo:](https://leetcode.com/articles/shortest-distance-to-a-character/)|Easy|

|842|[card-flipping-game](https://leetcode.com/problems/card-flipping-game)||[:memo:](https://leetcode.com/articles/card-flipping-game/)|Medium|

|843|[binary-trees-with-factors](https://leetcode.com/problems/binary-trees-with-factors)||[:memo:](https://leetcode.com/articles/binary-trees-with-factors/)|Medium|

|850|[insert-into-a-cyclic-sorted-list](https://leetcode.com/problems/insert-into-a-cyclic-sorted-list)|:lock:||Medium|

|851|[goat-latin](https://leetcode.com/problems/goat-latin)||[:memo:](https://leetcode.com/articles/goat-latin/)|Easy|

|852|[friends-of-appropriate-ages](https://leetcode.com/problems/friends-of-appropriate-ages)||[:memo:](https://leetcode.com/articles/friends-of-appropriate-ages/)|Medium|

|853|[most-profit-assigning-work](https://leetcode.com/problems/most-profit-assigning-work)||[:memo:](https://leetcode.com/articles/most-profit-assigning-work/)|Medium|

|854|[making-a-large-island](https://leetcode.com/problems/making-a-large-island)||[:memo:](https://leetcode.com/articles/making-a-large-island/)|Hard|

|855|[unique-letter-string](https://leetcode.com/problems/unique-letter-string)||[:memo:](https://leetcode.com/articles/unique-letter-string/)|Hard|

|856|[consecutive-numbers-sum](https://leetcode.com/problems/consecutive-numbers-sum)||[:memo:](https://leetcode.com/articles/consecutive-numbers-sum/)|Medium|

|857|[positions-of-large-groups](https://leetcode.com/problems/positions-of-large-groups)||[:memo:](https://leetcode.com/articles/positions-of-large-groups/)|Easy|

|858|[masking-personal-information](https://leetcode.com/problems/masking-personal-information)||[:memo:](https://leetcode.com/articles/masking-personal-information/)|Medium|

|859|[design-circular-deque](https://leetcode.com/problems/design-circular-deque)|||Medium|

|860|[design-circular-queue](https://leetcode.com/problems/design-circular-queue)|||Medium|

|861|[flipping-an-image](https://leetcode.com/problems/flipping-an-image)||[:memo:](https://leetcode.com/articles/flipping-an-image/)|Easy|

|862|[find-and-replace-in-string](https://leetcode.com/problems/find-and-replace-in-string)||[:memo:](https://leetcode.com/articles/find-and-replace-in-string/)|Medium|

|863|[sum-of-distances-in-tree](https://leetcode.com/problems/sum-of-distances-in-tree)||[:memo:](https://leetcode.com/articles/sum-of-distances-in-tree/)|Hard|

|864|[image-overlap](https://leetcode.com/problems/image-overlap)||[:memo:](https://leetcode.com/articles/image-overlap/)|Medium|

|865|[robot-room-cleaner](https://leetcode.com/problems/robot-room-cleaner)|:lock:||Hard|

|866|[rectangle-overlap](https://leetcode.com/problems/rectangle-overlap)||[:memo:](https://leetcode.com/articles/rectangle-overlap/)|Easy|

|867|[new-21-game](https://leetcode.com/problems/new-21-game)||[:memo:](https://leetcode.com/articles/new-21-game/)|Medium|

|868|[push-dominoes](https://leetcode.com/problems/push-dominoes)||[:memo:](https://leetcode.com/articles/push-dominoes/)|Medium|

|869|[similar-string-groups](https://leetcode.com/problems/similar-string-groups)||[:memo:](https://leetcode.com/articles/similar-string-groups/)|Hard|

|870|[magic-squares-in-grid](https://leetcode.com/problems/magic-squares-in-grid)||[:memo:](https://leetcode.com/articles/magic-squares-in-grid/)|Easy|

|871|[keys-and-rooms](https://leetcode.com/problems/keys-and-rooms)||[:memo:](https://leetcode.com/articles/keys-and-rooms/)|Medium|

|872|[split-array-into-fibonacci-sequence](https://leetcode.com/problems/split-array-into-fibonacci-sequence)||[:memo:](https://leetcode.com/articles/split-array-into-fibonacci-sequence/)|Medium|

|873|[guess-the-word](https://leetcode.com/problems/guess-the-word)||[:memo:](https://leetcode.com/articles/guess-the-word/)|Hard|

|874|[backspace-string-compare](https://leetcode.com/problems/backspace-string-compare)||[:memo:](https://leetcode.com/articles/backspace-string-compare/)|Easy|

|875|[longest-mountain-in-array](https://leetcode.com/problems/longest-mountain-in-array)||[:memo:](https://leetcode.com/articles/longest-mountain-in-array/)|Medium|

|876|[hand-of-straights](https://leetcode.com/problems/hand-of-straights)||[:memo:](https://leetcode.com/articles/hand-of-straights/)|Medium|

|877|[shortest-path-visiting-all-nodes](https://leetcode.com/problems/shortest-path-visiting-all-nodes)||[:memo:](https://leetcode.com/articles/shortest-path-visiting-all-nodes/)|Hard|

|878|[shifting-letters](https://leetcode.com/problems/shifting-letters)||[:memo:](https://leetcode.com/articles/shifting-letters/)|Medium|

|879|[maximize-distance-to-closest-person](https://leetcode.com/problems/maximize-distance-to-closest-person)||[:memo:](https://leetcode.com/articles/maximize-distance-to-closest-person/)|Easy|

|880|[rectangle-area-ii](https://leetcode.com/problems/rectangle-area-ii)||[:memo:](https://leetcode.com/articles/rectangle-area-ii/)|Hard|

|881|[loud-and-rich](https://leetcode.com/problems/loud-and-rich)||[:memo:](https://leetcode.com/articles/loud-and-rich/)|Medium|

|882|[peak-index-in-a-mountain-array](https://leetcode.com/problems/peak-index-in-a-mountain-array)||[:memo:](https://leetcode.com/articles/peak-index-in-a-mountain-array/)|Easy|

|883|[car-fleet](https://leetcode.com/problems/car-fleet)||[:memo:](https://leetcode.com/articles/car-fleet/)|Medium|

|884|[k-similar-strings](https://leetcode.com/problems/k-similar-strings)||[:memo:](https://leetcode.com/articles/k-similar-strings/)|Hard|

|885|[exam-room](https://leetcode.com/problems/exam-room)||[:memo:](https://leetcode.com/articles/exam-room/)|Medium|

|886|[score-of-parentheses](https://leetcode.com/problems/score-of-parentheses)||[:memo:](https://leetcode.com/articles/score-of-parentheses/)|Medium|

|887|[minimum-cost-to-hire-k-workers](https://leetcode.com/problems/minimum-cost-to-hire-k-workers)||[:memo:](https://leetcode.com/articles/minimum-cost-to-hire-k-workers/)|Hard|

|888|[mirror-reflection](https://leetcode.com/problems/mirror-reflection)||[:memo:](https://leetcode.com/articles/mirror-reflection/)|Medium|

|889|[buddy-strings](https://leetcode.com/problems/buddy-strings)||[:memo:](https://leetcode.com/articles/buddy-strings/)|Easy|

|890|[lemonade-change](https://leetcode.com/problems/lemonade-change)||[:memo:](https://leetcode.com/articles/lemonade-change/)|Easy|

|891|[score-after-flipping-matrix](https://leetcode.com/problems/score-after-flipping-matrix)||[:memo:](https://leetcode.com/articles/score-after-flipping-matrix/)|Medium|

|892|[shortest-subarray-with-sum-at-least-k](https://leetcode.com/problems/shortest-subarray-with-sum-at-least-k)||[:memo:](https://leetcode.com/articles/shortest-subarray-with-sum-atleast-k/)|Hard|

|893|[all-nodes-distance-k-in-binary-tree](https://leetcode.com/problems/all-nodes-distance-k-in-binary-tree)||[:memo:](https://leetcode.com/articles/all-nodes-distance-k-in-binary-tree/)|Medium|

|894|[random-pick-with-blacklist](https://leetcode.com/problems/random-pick-with-blacklist)||[:memo:](https://leetcode.com/articles/random-pick-with-blacklist/)|Hard|

|895|[shortest-path-to-get-all-keys](https://leetcode.com/problems/shortest-path-to-get-all-keys)||[:memo:](https://leetcode.com/articles/shortest-path-to-get-all-keys/)|Hard|

|896|[smallest-subtree-with-all-the-deepest-nodes](https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes)||[:memo:](https://leetcode.com/articles/smallest-subtree-with-all-the-deepest-nodes/)|Medium|

|897|[prime-palindrome](https://leetcode.com/problems/prime-palindrome)||[:memo:](https://leetcode.com/articles/prime-palindrome/)|Medium|

|898|[transpose-matrix](https://leetcode.com/problems/transpose-matrix)||[:memo:](https://leetcode.com/articles/transpose-matrix/)|Easy|

|899|[binary-gap](https://leetcode.com/problems/binary-gap)||[:memo:](https://leetcode.com/articles/binary-gap/)|Easy|

|900|[reordered-power-of-2](https://leetcode.com/problems/reordered-power-of-2)||[:memo:](https://leetcode.com/articles/reordered-power-of-2/)|Medium|

|901|[advantage-shuffle](https://leetcode.com/problems/advantage-shuffle)||[:memo:](https://leetcode.com/articles/advantage-shuffle/)|Medium|

|902|[minimum-number-of-refueling-stops](https://leetcode.com/problems/minimum-number-of-refueling-stops)||[:memo:](https://leetcode.com/articles/minimum-number-of-refueling-stops/)|Hard|

|903|[implement-rand10-using-rand7](https://leetcode.com/problems/implement-rand10-using-rand7)||[:memo:](https://leetcode.com/articles/implement-rand10-using-rand7/)|Medium|

|904|[leaf-similar-trees](https://leetcode.com/problems/leaf-similar-trees)||[:memo:](https://leetcode.com/articles/leaf-similar-trees/)|Easy|

|905|[length-of-longest-fibonacci-subsequence](https://leetcode.com/problems/length-of-longest-fibonacci-subsequence)||[:memo:](https://leetcode.com/articles/length-of-longest-fibonacci-subsequence/)|Medium|

|906|[walking-robot-simulation](https://leetcode.com/problems/walking-robot-simulation)||[:memo:](https://leetcode.com/articles/walking-robot-simulation/)|Easy|

|907|[koko-eating-bananas](https://leetcode.com/problems/koko-eating-bananas)||[:memo:](https://leetcode.com/articles/koko-eating-bananas/)|Medium|