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https://github.com/rodneyshag/leetcode_solutions

203 efficient solutions to LeetCode problems
https://github.com/rodneyshag/leetcode_solutions

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203 efficient solutions to LeetCode problems

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203 efficient solutions to LeetCode problems



| # | Question | Solution | Difficulty |
|:----:|:------------------------------------------------------------------------------------------------------------------------------------------------:|:---------------------------------------------------------------------------------------------------------------------------------------------------------------:|:----------:|
| 1 | [Two Sum](https://leetcode.com/problems/two-sum) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Two%20Sum.md) | Easy |
| 2 | [Add Two Numbers](https://leetcode.com/problems/add-two-numbers) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Add%20Two%20Numbers.md) | Medium |
| 4 | [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Median%20of%20Two%20Sorted%20Arrays.md) | Hard |
| 5 | [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Longest%20Palindromic%20Substring.md) | Medium |
| 7 | [Reverse Integer](https://leetcode.com/problems/reverse-integer) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20Integer.md) | Easy |
| 9 | [Palindrome Number](https://leetcode.com/problems/palindrome-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Palindrome%20Number.md) | Easy |
| 13 | [Roman to Integer](https://leetcode.com/problems/roman-to-integer) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Roman%20to%20Integer.md) | Easy |
| 14 | [Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Longest%20Common%20Prefix.md) | Easy |
| 15 | [3sum](https://leetcode.com/problems/3sum) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/3sum.md) | Medium |
| 16 | [3sum Closest](https://leetcode.com/problems/3sum-closest) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/3sum%20Closest.md) | Medium |
| 17 | [Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Letter%20Combinations%20of%20a%20Phone%20Number.md) | Medium |
| 19 | [Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Nth%20Node%20From%20End%20of%20List.md) | Medium |
| 20 | [Valid Parentheses](https://leetcode.com/problems/valid-parentheses) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Valid%20Parentheses.md) | Easy |
| 21 | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Merge%20Two%20Sorted%20Lists.md) | Easy |
| 22 | [Generate Parentheses](https://leetcode.com/problems/generate-parentheses) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Generate%20Parentheses.md) | Medium |
| 23 | [Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Merge%20k%20Sorted%20Lists.md) | Hard |
| 26 | [Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Duplicates%20from%20Sorted%20Array.md) | Easy |
| 27 | [Remove Element](https://leetcode.com/problems/remove-element) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Element.md) | Easy |
| 28 | [Implement strStr()](https://leetcode.com/problems/implement-strstr) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Implement%20strStr.md) | Easy |
| 33 | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Search%20in%20Rotated%20Sorted%20Array.md) | 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) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20First%20and%20Last%20Position%20of%20Element%20in%20Sorted%20Array.md) | Medium |
| 35 | [Search Insert Position](https://leetcode.com/problems/search-insert-position) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Search%20Insert%20Position.md) | Easy |
| 38 | [Count and Say](https://leetcode.com/problems/count-and-say) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Count%20and%20Say.md) | Easy |
| 42 | [Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Trapping%20Rain%20Water.md) | Hard |
| 46 | [Permutations](https://leetcode.com/problems/permutations) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Permutations.md) | Medium |
| 47 | [Permutations II](https://leetcode.com/problems/permutations-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Permutations%20II.md) | Medium |
| 48 | [Rotate Image](https://leetcode.com/problems/rotate-image) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Rotate%20Image.md) | Medium |
| 49 | [Group Anagrams](https://leetcode.com/problems/group-anagrams) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Group%20Anagrams.md) | Medium |
| 51 | [N-Queens](https://leetcode.com/problems/n-queens) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/N-Queens.md) | Hard |
| 52 | [N-Queens II](https://leetcode.com/problems/n-queens-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/N-Queens%20II.md) | Hard |
| 53 | [Maximum Subarray](https://leetcode.com/problems/maximum-subarray) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Maximum%20Subarray.md) | Easy |
| 55 | [Jump Game](https://leetcode.com/problems/jump-game) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Jump%20Game.md) | Medium |
| 58 | [Length of Last Word](https://leetcode.com/problems/length-of-last-word) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Length%20of%20Last%20Word.md) | Easy |
| 62 | [Unique Paths](https://leetcode.com/problems/unique-paths) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Unique%20Paths.md) | Medium |
| 63 | [Unique Paths II](https://leetcode.com/problems/unique-paths-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Unique%20Paths%20II.md) | Medium |
| 66 | [Plus One](https://leetcode.com/problems/plus-one) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Plus%20One.md) | Easy |
| 67 | [Add Binary](https://leetcode.com/problems/add-binary) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Add%20Binary.md) | Easy |
| 69 | [Sqrt(x)](https://leetcode.com/problems/sqrtx) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sqrt(x).md) | Easy |
| 70 | [Climbing Stairs](https://leetcode.com/problems/climbing-stairs) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Climbing%20Stairs.md) | Easy |
| 73 | [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Set%20Matrix%20Zeroes.md) | Medium |
| 78 | [Subsets](https://leetcode.com/problems/subsets) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Subsets.md) | Medium |
| 80 | [Remove Duplicates from Sorted Array II](https://leetcode.com/problems/remove-duplicates-from-sorted-array-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Duplicates%20from%20Sorted%20Array%20II.md) | Medium |
| 81 | [Search in Rotated Sorted Array II](https://leetcode.com/problems/search-in-rotated-sorted-array-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Search%20in%20Rotated%20Sorted%20Array%20II.md) | Medium |
| 82 | [Remove Duplicates from Sorted List II](https://leetcode.com/problems/remove-duplicates-from-sorted-list-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Duplicates%20from%20Sorted%20List%20II.md) | Medium |
| 83 | [Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Duplicates%20from%20Sorted%20List.md) | Easy |
| 88 | [Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Merge%20Sorted%20Array.md) | Easy |
| 90 | [Subsets II](https://leetcode.com/problems/subsets-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Subsets%20II.md) | Medium |
| 92 | [Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20Linked%20List%20II.md) | Medium |
| 94 | [Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Tree%20Inorder%20Traversal.md) | Medium |
| 98 | [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Validate%20Binary%20Search%20Tree.md) | Medium |
| 100 | [Same Tree](https://leetcode.com/problems/same-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Same%20Tree.md) | Easy |
| 101 | [Symmetric Tree](https://leetcode.com/problems/symmetric-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Symmetric%20Tree.md) | Easy |
| 102 | [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Tree%20Level%20Order%20Traversal.md) | Medium |
| 104 | [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Maximum%20Depth%20of%20Binary%20Tree.md) | Easy |
| 107 | [Binary Tree Level Order Traversal II](https://leetcode.com/problems/binary-tree-level-order-traversal-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Tree%20Level%20Order%20Traversal%20II.md) | Easy |
| 108 | [Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Convert%20Sorted%20Array%20to%20Binary%20Search%20Tree.md) | Easy |
| 110 | [Balanced Binary Tree](https://leetcode.com/problems/balanced-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Balanced%20Binary%20Tree.md) | Easy |
| 111 | [Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Minimum%20Depth%20of%20Binary%20Tree.md) | Easy |
| 118 | [Pascal's Triangle](https://leetcode.com/problems/pascals-triangle) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Pascal%27s%20Triangle.md) | Easy |
| 119 | [Pascal's Triangle II](https://leetcode.com/problems/pascals-triangle-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Pascal%27s%20Triangle%20II.md) | Easy |
| 121 | [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Best%20Time%20to%20Buy%20and%20Sell%20Stock.md) | Easy |
| 122 | [Best Time to Buy and Sell Stock II](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Best%20Time%20to%20Buy%20and%20Sell%20Stock%20II.md) | Easy |
| 125 | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Valid%20Palindrome.md) | Easy |
| 127 | [Word Ladder](https://leetcode.com/problems/word-ladder) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Word%20Ladder.md) | Medium |
| 136 | [Single Number](https://leetcode.com/problems/single-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Single%20Number.md) | Easy |
| 139 | [Word Break](https://leetcode.com/problems/word-break) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Word%20Break.md) | Medium |
| 141 | [Linked List Cycle](https://leetcode.com/problems/linked-list-cycle) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Linked%20List%20Cycle.md) | Easy |
| 142 | [Linked List Cycle II](https://leetcode.com/problems/linked-list-cycle-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Linked%20List%20Cycle%20II.md) | Medium |
| 143 | [Reorder List](https://leetcode.com/problems/reorder-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reorder%20List.md) | Medium |
| 144 | [Binary Tree Preorder Traversal](https://leetcode.com/problems/binary-tree-preorder-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Tree%20Preorder%20Traversal.md) | Medium |
| 145 | [Binary Tree Postorder Traversal](https://leetcode.com/problems/binary-tree-postorder-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Tree%20Postorder%20Traversal.md) | Hard |
| 146 | [LRU Cache](https://leetcode.com/problems/lru-cache) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/LRU%20Cache.md) | Medium |
| 148 | [Sort List](https://leetcode.com/problems/sort-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sort%20List.md) | Medium |
| 149 | [Max Points on a Line](https://leetcode.com/problems/max-points-on-a-line) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Max%20Points%20on%20a%20Line.md) | Hard |
| 151 | [Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20Words%20in%20a%20String.md) | Medium |
| 155 | [Min Stack](https://leetcode.com/problems/min-stack) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Min%20Stack.md) | Easy |
| 160 | [Intersection of Two linked Lists](https://leetcode.com/problems/intersection-of-two-linked-lists) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Intersection%20of%20Two%20linked%20Lists.md) | Easy |
| 162 | [Find Peak Element](https://leetcode.com/problems/find-peak-element) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20Peak%20Element.md) | Medium |
| 167 | [Two Sum II - Input array is sorted](https://leetcode.com/problems/two-sum-ii-input-array-is-sorted) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Two%20Sum%20II%20-%20Input%20array%20is%20sorted.md) | Easy |
| 168 | [Excel Sheet Column Title](https://leetcode.com/problems/excel-sheet-column-title) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Excel%20Sheet%20Column%20Title.md) | Easy |
| 169 | [Majority Element](https://leetcode.com/problems/majority-element) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Majority%20Element.md) | Easy |
| 171 | [Excel Sheet Column Number](https://leetcode.com/problems/excel-sheet-column-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Excel%20Sheet%20Column%20Number.md) | Easy |
| 172 | [Factorial Trailing Zeroes](https://leetcode.com/problems/factorial-trailing-zeroes) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Factorial%20Trailing%20Zeroes.md) | Easy |
| 175 | [Combine Two Tables](https://leetcode.com/problems/combine-two-tables) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Combine%20Two%20Tables.md) | Easy |
| 176 | [Second Highest Salary](https://leetcode.com/problems/second-highest-salary) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Second%20Highest%20Salary.md) | Easy |
| 177 | [Nth Highest Salary](https://leetcode.com/problems/nth-highest-salary) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Nth%20Highest%20Salary.md) | Medium |
| 178 | [Rank Scores](https://leetcode.com/problems/rank-scores) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Rank%20Scores.md) | Medium |
| 180 | [Consecutive Numbers](https://leetcode.com/problems/consecutive-numbers) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Consecutive%20Numbers.md) | Medium |
| 181 | [Employees Earning More Than Their Managers](https://leetcode.com/problems/employees-earning-more-than-their-managers) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Employees%20Earning%20More%20Than%20Their%20Managers.md) | Easy |
| 182 | [Duplicate Emails](https://leetcode.com/problems/duplicate-emails) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Duplicate%20Emails.md) | Easy |
| 183 | [Customers Who Never Order](https://leetcode.com/problems/customers-who-never-order) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Customers%20Who%20Never%20Order.md) | Easy |
| 184 | [Department Highest Salary](https://leetcode.com/problems/department-highest-salary) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Department%20Highest%20Salary.md) | Medium |
| 185 | [Department Top Three Salaries](https://leetcode.com/problems/department-top-three-salaries) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Department%20Top%20Three%20Salaries.md) | Hard |
| 189 | [Rotate Array](https://leetcode.com/problems/rotate-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Rotate%20Array.md) | Easy |
| 190 | [Reverse Bits](https://leetcode.com/problems/reverse-bits) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20Bits.md) | Easy |
| 191 | [Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Number%20of%201%20Bits.md) | Easy |
| 196 | [Delete Duplicate Emails](https://leetcode.com/problems/delete-duplicate-emails) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Delete%20Duplicate%20Emails.md) | Easy |
| 197 | [Rising Temperature](https://leetcode.com/problems/rising-temperature) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Rising%20Temperature.md) | Easy |
| 198 | [House Robber](https://leetcode.com/problems/house-robber) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/House%20Robber.md) | Easy |
| 200 | [Number of Islands](https://leetcode.com/problems/number-of-islands) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Number%20of%20Islands.md) | Medium |
| 202 | [Happy Number](https://leetcode.com/problems/happy-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Happy%20Number.md) | Easy |
| 203 | [Remove Linked List Elements](https://leetcode.com/problems/remove-linked-list-elements) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Remove%20Linked%20List%20Elements.md) | Easy |
| 204 | [Count Primes](https://leetcode.com/problems/count-primes) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Count%20Primes.md) | Easy |
| 206 | [Reverse Linked List](https://leetcode.com/problems/reverse-linked-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20Linked%20List.md) | Easy |
| 207 | [Course Schedule](https://leetcode.com/problems/course-schedule) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Course%20Schedule.md) | Medium |
| 208 | [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Implement%20Trie%20(Prefix%20Tree).md) | Medium |
| 210 | [Course Schedule II](https://leetcode.com/problems/course-schedule-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Course%20Schedule%20II.md) | Medium |
| 217 | [Contains Duplicate](https://leetcode.com/problems/contains-duplicate) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Contains%20Duplicate.md) | Easy |
| 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Invert%20Binary%20Tree.md) | Easy |
| 231 | [Power of Two](https://leetcode.com/problems/power-of-two) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Power%20of%20Two.md) | Easy |
| 232 | [Implement Queue using Stacks](https://leetcode.com/problems/implement-queue-using-stacks) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Implement%20Queue%20using%20Stacks.md) | Easy |
| 234 | [Palindrome Linked List](https://leetcode.com/problems/palindrome-linked-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Palindrome%20Linked%20List.md) | Easy |
| 235 | [Lowest Common Ancestor of a Binary Search Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Lowest%20Common%20Ancestor%20of%20a%20Binary%20Search%20Tree.md) | Easy |
| 236 | [Lowest Common Ancestor of a Binary Tree](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Lowest%20Common%20Ancestor%20of%20a%20Binary%20Tree.md) | Medium |
| 237 | [Delete Node in a Linked List](https://leetcode.com/problems/delete-node-in-a-linked-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Delete%20Node%20in%20a%20Linked%20List.md) | Easy |
| 238 | [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Product%20of%20Array%20Except%20Self.md) | Medium |
| 239 | [Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sliding%20Window%20Maximum.md) | Hard |
| 240 | [Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Search%20a%202D%20Matrix%20II.md) | Medium |
| 242 | [Valid Anagram](https://leetcode.com/problems/valid-anagram) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Valid%20Anagram.md) | Easy |
| 262 | [Trips and Users](https://leetcode.com/problems/trips-and-users) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Trips%20and%20Users.md) | Hard |
| 263 | [Ugly Number](https://leetcode.com/problems/ugly-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Ugly%20Number.md) | Easy |
| 264 | [Ugly Number II](https://leetcode.com/problems/ugly-number-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Ugly%20Number%20II.md) | Medium |
| 268 | [Missing Number](https://leetcode.com/problems/missing-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Missing%20Number.md) | Easy |
| 273 | [Integer to English Words](https://leetcode.com/problems/integer-to-english-words) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Integer%20to%20English%20Words.md) | Hard |
| 278 | [First Bad Version](https://leetcode.com/problems/first-bad-version) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/First%20Bad%20Version.md) | Easy |
| 283 | [Move Zeroes](https://leetcode.com/problems/move-zeroes) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Move%20Zeroes.md) | Easy |
| 290 | [Word Pattern](https://leetcode.com/problems/word-pattern) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Word%20Pattern.md) | Easy |
| 292 | [Nim Game](https://leetcode.com/problems/nim-game) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Nim%20Game.md) | Easy |
| 295 | [Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20Median%20from%20Data%20Stream.md) | Hard |
| 300 | [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Longest%20Increasing%20Subsequence.md) | Medium |
| 303 | [Range Sum Query - Immutable](https://leetcode.com/problems/range-sum-query-immutable) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Range%20Sum%20Query%20-%20Immutable.md) | Easy |
| 309 | [Best Time to Buy and Sell Stock with Cooldown](https://leetcode.com/problems/best-time-to-buy-and-sell-stock-with-cooldown) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Best%20Time%20to%20Buy%20and%20Sell%20Stock%20with%20Cooldown.md) | Medium |
| 326 | [Power of Three](https://leetcode.com/problems/power-of-three) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Power%20of%20Three.md) | Easy |
| 328 | [Odd Even Linked List](https://leetcode.com/problems/odd-even-linked-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Odd%20Even%20Linked%20List.md) | Medium |
| 342 | [Power of Four](https://leetcode.com/problems/power-of-four) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Power%20of%20Four.md) | Easy |
| 344 | [Reverse String](https://leetcode.com/problems/reverse-string) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reverse%20String.md) | Easy |
| 347 | [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Top%20K%20Frequent%20Elements.md) | Medium |
| 349 | [Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Intersection%20of%20Two%20Arrays.md) | Easy |
| 350 | [Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Intersection%20of%20Two%20Arrays%20II.md) | Easy |
| 354 | [Russian Doll Envelopes](https://leetcode.com/problems/russian-doll-envelopes) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Russian%20Doll%20Envelopes.md) | Hard |
| 367 | [Valid Perfect Square](https://leetcode.com/problems/valid-perfect-square) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Valid%20Perfect%20Square.md) | Easy |
| 371 | [Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sum%20of%20Two%20Integers.md) | Easy |
| 380 | [Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Insert%20Delete%20GetRandom%20O%281%29.md) | Medium |
| 381 | [Insert Delete GetRandom O(1) - Duplicates allowed](https://leetcode.com/problems/insert-delete-getrandom-o1-duplicates-allowed) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Insert%20Delete%20GetRandom%20O%281%29%20-%20Duplicates%20allowed.md) | Hard |
| 383 | [Ransom Note](https://leetcode.com/problems/ransom-note) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Ransom%20Note.md) | Easy |
| 384 | [Shuffle an Array](https://leetcode.com/problems/shuffle-an-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Shuffle%20an%20Array.md) | Medium |
| 387 | [First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/First%20Unique%20Character%20in%20a%20String.md) | Easy |
| 389 | [Find the Difference](https://leetcode.com/problems/find-the-difference) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20the%20Difference.md) | Easy |
| 412 | [Fizz Buzz](https://leetcode.com/problems/fizz-buzz) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Fizz%20Buzz.md) | Easy |
| 414 | [Third Maximum Number](https://leetcode.com/problems/third-maximum-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Third%20Maximum%20Number.md) | Easy |
| 429 | [N-ary Tree Level Order Traversal](https://leetcode.com/problems/n-ary-tree-level-order-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/N-ary%20Tree%20Level%20Order%20Traversal.md) | Easy |
| 437 | [Path Sum III](https://leetcode.com/problems/path-sum-iii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Path%20Sum%20III.md) | Easy |
| 442 | [Find All Duplicates in an Array](https://leetcode.com/problems/find-all-duplicates-in-an-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20All%20Duplicates%20in%20an%20Array.md) | Medium |
| 443 | [String Compression](https://leetcode.com/problems/string-compression) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/String%20Compression.md) | Easy |
| 445 | [Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Add%20Two%20Numbers%20II.md) | Medium |
| 448 | [Find All Numbers Disappeared in an Array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Find%20All%20Numbers%20Disappeared%20in%20an%20Array.md) | Easy |
| 454 | [4Sum II](https://leetcode.com/problems/4sum-ii) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/4Sum%20II.md) | Medium |
| 461 | [Hamming Distance](https://leetcode.com/problems/hamming-distance) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Hamming%20Distance.md) | Easy |
| 470 | [Implement Rand10() Using Rand7()](https://leetcode.com/problems/implement-rand10-using-rand7) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Implement%20Rand10()%20Using%20Rand7().md) | Medium |
| 477 | [Total Hamming Distance](https://leetcode.com/problems/total-hamming-distance) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Total%20Hamming%20Distance.md) | Medium |
| 480 | [Sliding Window Median](https://leetcode.com/problems/sliding-window-median) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sliding%20Window%20Median.md) | Hard |
| 500 | [Keyboard Row](https://leetcode.com/problems/keyboard-row) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Keyboard%20Row.md) | Easy |
| 509 | [Fibonacci Number](https://leetcode.com/problems/fibonacci-number) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Fibonacci%20Number.md) | Easy |
| 516 | [Longest Palindromic Subsequence](https://leetcode.com/problems/longest-palindromic-subsequence) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Longest%20Palindromic%20Subsequence.md) | Medium |
| 518 | [Coin Change 2](https://leetcode.com/problems/coin-change-2) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Coin%20Change%202.md) | Medium |
| 520 | [Detect Capital](https://leetcode.com/problems/detect-capital) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Detect%20Capital.md) | Easy |
| 525 | [Contiguous Array](https://leetcode.com/problems/contiguous-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Contiguous%20Array.md) | Medium |
| 543 | [Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Diameter%20of%20Binary%20Tree.md) | Easy |
| 559 | [Maximum Depth of N-ary Tree](https://leetcode.com/problems/maximum-depth-of-n-ary-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Maximum%20Depth%20of%20N-ary%20Tree.md) | Easy |
| 560 | [Subarray Sum Equals K](https://leetcode.com/problems/subarray-sum-equals-k) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Subarray%20Sum%20Equals%20K.md) | Medium |
| 572 | [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Subtree%20of%20Another%20Tree.md) | Easy |
| 581 | [Shortest Unsorted Continuous Subarray](https://leetcode.com/problems/shortest-unsorted-continuous-subarray) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Shortest%20Unsorted%20Continuous%20Subarray.md) | Easy |
| 589 | [N-ary Tree Preorder Traversal](https://leetcode.com/problems/n-ary-tree-preorder-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/N-ary%20Tree%20Preorder%20Traversal.md) | Easy |
| 590 | [N-ary Tree Postorder Traversal](https://leetcode.com/problems/n-ary-tree-postorder-traversal) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/N-ary%20Tree%20Postorder%20Traversal.md) | Easy |
| 595 | [Big Countries](https://leetcode.com/problems/big-countries) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Big%20Countries.md) | Easy |
| 596 | [Classes More Than 5 Students](https://leetcode.com/problems/classes-more-than-5-students) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Classes%20More%20Than%205%20Students.md) | Easy |
| 601 | [Human Traffic of Stadium](https://leetcode.com/problems/human-traffic-of-stadium) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Human%20Traffic%20of%20Stadium.md) | Hard |
| 617 | [Merge Two Binary Trees](https://leetcode.com/problems/merge-two-binary-trees) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Merge%20Two%20Binary%20Trees.md) | Easy |
| 620 | [Not Boring Movies](https://leetcode.com/problems/not-boring-movies) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Not%20Boring%20Movies.md) | Easy |
| 626 | [Exchange Seats](https://leetcode.com/problems/exchange-seats) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Exchange%20Seats.md) | Medium |
| 627 | [Swap Salary](https://leetcode.com/problems/swap-salary) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Swap%20Salary.md) | Easy |
| 692 | [Top K Frequent Words](https://leetcode.com/problems/top-k-frequent-words) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Top%20K%20Frequent%20Words.md) | Medium |
| 695 | [Max Area of Island](https://leetcode.com/problems/max-area-of-island) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Max%20Area%20of%20Island.md) | Medium |
| 703 | [Kth Largest Element in a Stream](https://leetcode.com/problems/kth-largest-element-in-a-stream) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Kth%20Largest%20Element%20in%20a%20Stream.md) | Easy |
| 704 | [Binary Search](https://leetcode.com/problems/binary-search) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Binary%20Search.md) | Easy |
| 706 | [Design HashMap](https://leetcode.com/problems/design-hashmap) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Design%20HashMap.md) | Easy |
| 707 | [Design Linked List](https://leetcode.com/problems/design-linked-list) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Design%20Linked%20List.md) | Easy |
| 709 | [To Lower Case](https://leetcode.com/problems/to-lower-case) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/To%20Lower%20Case.md) | Easy |
| 733 | [Flood Fill](https://leetcode.com/problems/flood-fill) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Flood%20Fill.md) | Easy |
| 771 | [Jewels and Stones](https://leetcode.com/problems/jewels-and-stones) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Jewels%20and%20Stones.md) | Easy |
| 895 | [Maximum Frequency Stack](https://leetcode.com/problems/maximum-frequency-stack) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Maximum%20Frequency%20Stack.md) | Hard |
| 912 | [Sort an Array](https://leetcode.com/problems/sort-an-array) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Sort%20an%20Array.md) | Medium |
| 976 | [Largest Perimeter Triangle](https://leetcode.com/problems/largest-perimeter-triangle) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Largest%20Perimeter%20Triangle.md) | Easy |
| 1010 | [Pairs of Songs With Total Durations Divisible by 60](https://leetcode.com/problems/pairs-of-songs-with-total-durations-divisible-by-60) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Pairs%20of%20Songs%20With%20Total%20Durations%20Divisible%20by%2060.md) | Easy |
| 1092 | [Shortest Common Supersequence](https://leetcode.com/problems/shortest-common-supersequence) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Shortest%20Common%20Supersequence.md) | Hard |
| 1114 | [Print in Order](https://leetcode.com/problems/print-in-order) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Print%20in%20Order.md) | Easy |
| 1115 | [Print FooBar Alternately](https://leetcode.com/problems/print-foobar-alternately) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Print%20FooBar%20Alternately.md) | Medium |
| 1116 | [Print Zero Even Odd](https://leetcode.com/problems/print-zero-even-odd) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Print%20Zero%20Even%20Odd.md) | Medium |
| 1117 | [Building H2O](https://leetcode.com/problems/building-h2o) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Building%20H2O.md) | Medium |
| 1139 | [Largest 1-Bordered Square](https://leetcode.com/problems/largest-1-bordered-square) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Largest%201-Bordered%20Square.md) | Medium |
| 1179 | [Reformat Department Table](https://leetcode.com/problems/reformat-department-table) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Reformat%20Department%20Table.md) | Easy |
| 1195 | [Fizz Buzz Multithreaded](https://leetcode.com/problems/fizz-buzz-multithreaded) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Fizz%20Buzz%20Multithreaded.md) | Medium |
| 1207 | [Unique Number of Occurrences](https://leetcode.com/problems/unique-number-of-occurrences) | [Solution](https://github.com/RodneyShag/LeetCode_solutions/blob/master/Solutions/Unique%20Number%20of%20Occurrences.md) | Easy |