https://github.com/ryanfehr/leetcode

Leetcode problem solutions in Java
https://github.com/ryanfehr/leetcode

Last synced: about 1 year ago
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Leetcode problem solutions in Java

• Host: GitHub
• URL: https://github.com/ryanfehr/leetcode
• Owner: RyanFehr
• License: gpl-3.0
• Created: 2017-08-20T00:51:41.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2017-12-23T16:54:10.000Z (over 8 years ago)
• Last Synced: 2025-04-05T08:03:48.776Z (over 1 year ago)
• Language: Java
• Homepage:
• Size: 47.9 KB
• Stars: 6
• Watchers: 4
• Forks: 3
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
[CopyrightLicense]:https://github.com/RyanFehr/LeetCode/blob/master/LICENSE



	





    Solutions to problems on LeetCode.





	

    

    

    

	



Pages 1 [2](./indexing/page2.md) [3](./indexing/page3.md)

| #  | Title           |  Solution       |  Time           | Space           | Difficulty    | Note

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

| 1 |[Two Sum](https://leetcode.com/problems/two-sum/description/)| 


[Java](./Solutions/Two%20Sum/Solution.java)

 | _O(n)_ | _O(n)_| Easy | ||

| 2 |[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/description/)| 


[Java](./Solutions/Add%20Two%20Numbers/Solution.java)

 | _O(n)_ | _O(1)_| Easy | ||

| 3 |[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/description/)| 


[Java](./Solutions/Longest%20Substring%20Without%20Repeating%20Characters/Solution.java)

 | _O(n)_ | _O(n)_| Medium | ||

| 4 |[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/description/)| 




 | | | Hard | ||

| 5 |[Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/description/)| 




 | | | Medium | ||

| 6 |[ZigZag Conversion](https://leetcode.com/problems/zigzag-conversion/description/)| 




 | | | Medium | ||

| 7 |[Reverse Integer](https://leetcode.com/problems/reverse-integer/description/)| 


[Java](./Solutions/Reverse%20Integer/Solution.java)

 | _O(n)_ | _O(n)_| Easy | ||

| 8 |[String to Integer atoi](https://leetcode.com/problems/string-to-integer-atoi/description/)| 




 | | | Medium | ||

| 9 |[Palindrome Number](https://leetcode.com/problems/palindrome-number/description/)| 




 | | | Easy | ||

| 10 |[Regular Expression Matching](https://leetcode.com/problems/regular-expression-matching/description/)| 




 | | | Hard | ||

| 11 |[Container With Most Water](https://leetcode.com/problems/container-with-most-water/description/)| 




 | | | Medium | ||

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




 | | | Medium | ||

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




 | | | Easy | ||

| 14 |[Longest Common Prefix](https://leetcode.com/problems/longest-common-prefix/description/)| 




 | | | Easy | ||

| 15 |[3Sum](https://leetcode.com/problems/3sum/description/)| 




 | | | Medium | ||

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




 | | | Medium | ||

| 17 |[Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/)| 




 | | | Medium | ||

| 18 |[4Sum](https://leetcode.com/problems/4sum/description/)| 




 | | | Medium | ||

| 19 |[Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/description/)| 




 | | | Medium | ||

| 20 |[Valid Parentheses](https://leetcode.com/problems/valid-parentheses/description/)| 




 | | | Easy | ||

| 21 |[Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/description/)| 




 | | | Easy | ||

| 22 |[Generate Parentheses](https://leetcode.com/problems/generate-parentheses/description/)| 




 | | | Medium | ||

| 23 |[Merge k Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/description/)| 




 | | | Hard | ||

| 24 |[Swap Nodes in Pairs](https://leetcode.com/problems/swap-nodes-in-pairs/description/)| 




 | | | Medium | ||

| 25 |[Reverse Nodes in k-Group](https://leetcode.com/problems/reverse-nodes-in-k-group/description/)| 




 | | | Hard | ||

| 26 |[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/)| 




 | | | Easy | ||

| 27 |[Remove Element](https://leetcode.com/problems/remove-element/description/)| 




 | | | Easy | ||

| 28 |[Implement strStr()](https://leetcode.com/problems/implement-strstr/description/)| 




 | | | Easy | ||

| 29 |[Divide Two Integers](https://leetcode.com/problems/divide-two-integers/description/)| 




 | | | Medium | ||

| 30 |[Substring with Concatenation of All Words](https://leetcode.com/problems/substring-with-concatenation-of-all-words/description/)| 




 | | | Hard | ||

| 31 |[Next Permutation](https://leetcode.com/problems/next-permutation/description/)| 




 | | | Medium | ||

| 32 |[Longest Valid Parentheses](https://leetcode.com/problems/longest-valid-parentheses/description/)| 




 | | | Hard | ||

| 33 |[Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/description/)| 




 | | | Medium | ||

| 34 |[Search for a Range](https://leetcode.com/problems/search-for-a-range/description/)| 




 | | | Medium | ||

| 35 |[Search Insert Position](https://leetcode.com/problems/search-insert-position/description/)| 




 | | | Easy | ||

| 36 |[Valid Sudoku](https://leetcode.com/problems/valid-sudoku/description/)| 




 | | | Medium | ||

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




 | | | Hard | ||

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




 | | | Easy | ||

| 39 |[Combination Sum](https://leetcode.com/problems/combination-sum/description/)| 




 | | | Medium | ||

| 40 |[Combination Sum II](https://leetcode.com/problems/combination-sum-ii/description/)| 




 | | | Medium | ||

| 41 |[First Missing Positive](https://leetcode.com/problems/first-missing-positive/description/)| 




 | | | Hard | ||

| 42 |[Trapping Rain Water](https://leetcode.com/problems/trapping-rain-water/description/)| 




 | | | Hard | ||

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




 | | | Medium | ||

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




 | | | Hard | ||

| 45 |[Jump Game II](https://leetcode.com/problems/jump-game-ii/description/)| 




 | | | Hard | ||

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




 | | | Medium | ||

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




 | | | Medium | ||

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




 | | | Medium | ||

| 49 |[Group Anagrams](https://leetcode.com/problems/group-anagrams/description/)| 




 | | | Medium | ||

| 50 |[Pow(x,n)](https://leetcode.com/problems/powx-n/description/)| 




 | | | Medium | ||


Pages 1 [2](./indexing/page2.md) [3](./indexing/page3.md)