- Easy
- 1. Two sum -> Problem Description
- 9. Palindrome number -> Problem Description
- 13. Roman to interger -> Problem Description
- 14. Longest common prefix -> Problem Description
- 20. Valid parentheses -> Problem Description
- 21. Merge two sorted lists -> Problem Description
- 26. Remove duplicates from sorted array -> Problem Description
- 27. Remove element -> Problem Description
- 28. Implement strStr() -> Problem Description
- 35. Search insert position -> Problem Description
- 58. Length of last word -> Problem Description
- 66. Plus one -> Problem Description
- 67. Add binary -> Problem Description
- 69. Sqrt(x) -> Problem Description
- 70. Climbing stairs -> Problem Description
- 83. Remove duplicates from sorted list -> Problem Description
- 88. Merge sorted array -> Problem Description
- 94. Binary tree inorder traversal -> Problem Description
- 100. Same tree -> Problem Description
- 101. Symmetric tree -> Problem Description
- 104. Maximum depth of binary tree -> Problem Description
- 108. Convert sorted array to binary search tree
- 110. Balanced binary tree
- 111. Minimum depth of binary tree -> Problem Description
- 112. Path sum -> Problem Description
- 118. Pascal's triangle -> Problem Description
- 119. Pascal's triangle II -> Problem Description
- 121. Best time to buy and sell stock -> Problem Description
- 125. Valid palindrome -> Problem Description
- 141. Linked list cycle -> Problem Description
- 150. Evaluate reverse polish notation -> Problem Description
- 155. Min stack -> Problem Description
- 206. Reverse linked list -> Problem Description
- 217. Contains duplicate -> Problem Description
- 226. Invert binary tree -> Problem Description
- 234. Palindrome linked list -> Problem Description
- 242. Valid anagram -> Problem Description
- 543. Diameter of binary tree -> Problem Description
- 572. Subtree of another tree -> Problem Description
- 703. Kth largest element in a stream -> Problem Description
- 704. Binary search -> Problem Description
- 746. Min cost climbing stairs -> Problem Description
- 1046. Last stone weight -> Problem Description
- Medium
- 2. Add two numbers -> Problem Description
- 3. Longest substring without repeating characters -> Problem Description
- 5. Longest palindromic substring -> Problem Description
- 11. Container with most water -> Problem Description
- 15. Three sum -> Problem Description
- 16. Three sum closest
- 17. Letter combinations of a phone number -> Problem Description
- 19. Remove nth node from end of list
- 22. Generate parentheses -> Problem Description
- 36. Valid sudoku -> Problem Description
- 39. Combination sum -> Problem Description
- 40. Combination sum II -> Problem Description
- 45. Jump game II -> Problem Description
- 46. Permutations -> Problem Description
- 49. Group anagrams -> Problem Description
- 53. Maximum subarray -> Problem Description
- 55. Jump game -> Problem Description
- 74. Search a 2D matrix -> Problem Description
- 78. Subsets -> Problem Description
- 79. Word search -> Problem Description
- 90. Subsets II -> Problem Description
- 91. Decode ways -> Problem Description
- 98. Validate binary search tree -> Problem Description
- 102. Binary tree level order traversal -> Problem Description
- 105. Construct binary tree from preorder and inorder traversal -> Problem Description
- 128. Longest consecutive sequence -> Problem Description
- 130. Surrounded regions -> Problem Description
- 131. Palindrome partitioning -> Problem Description
- 133. Clone graph -> Problem Description
- 134. Gas station -> Problem Description
- 138. Copy list with random pointer PYTHON Solution -> Problem Description
- 139. Word break -> Problem Description
- 143. Reorder list -> Problem Description
- 146. LRU cache -> Problem Description
- 152. Maximum product subarray -> Problem Description
- 153. Find minimum in rotated sorted array -> Problem Description
- 167. Two sum II - input array is sorted -> Problem Description
- 198. House robber -> Problem Description
- 199. Binary tree right side view -> Problem Description
- 200. Number of islands -> Problem Description
- 208. Implement trie (prefix tree) -> Problem Description
- 211. Design add and search words data structure -> Problem Description
- 213. House robber II -> Problem Description
- 215. Kth largest element in an array -> Problem Description
- 230. Kth smallest element in a BST -> Problem Description
- 235. Lowest common ancestor of a binary search tree -> Problem Description
- 238. Product of array except self -> Problem Description
- 271. Encode and decode strings -> Problem Description
- 286. Walls and gates -> Problem Description
- 287. Find the duplicate number -> Problem Description
- 300. Longest increasing subsequence -> Problem Description
- 322. Coin change -> Problem Description
- 347. Top k frequent elements -> Problem Description
- 355. Design twitter -> Problem Description
- 416. Partition equal subset sum -> Problem Description
- 417. Pacific atlantic water flow -> Problem Description
- 424. Longest repeating character replacement -> Problem Description
- 567. Permutation in string -> Problem Description
- 621. Task scheduler -> Problem Description
- 647. Palindromic substrings -> Problem Description
- 678. Valid parenthesis string -> Problem Description
- 695. Max area of island -> Problem Description
- 739. Daily temperatures -> Problem Description
- 763. Partition labels -> Problem Description
- 846. Hand of straights -> Problem Description
- 853. Car fleet -> Problem Description
- 875. Koko eating bananas -> Problem Description
- 973. K closest points to origin -> Problem Description
- 981. Time based key-value store -> Problem Description
- 994. Rotting oranges -> Problem Description
- 1448. Count good nodes in binary tree -> Problem Description
- 1899. Merge triplets to form target triplet -> Problem Description
- Hard
- 4. Median of two sorted arrays -> Problem Description
- 23. Merge k sorted lists -> Problem Description
- 25. Reverse nodes in k-group -> Problem Description
- 42. Trapping rain water -> Problem Description
- 51. N-queens -> Problem Description
- 76. Minimum window substring -> Problem Description
- 84. Largest rectangle in histogram -> Problem Description
- 212. Word search II -> Problem Description
- 239. Sliding window maximum -> Problem Description
- 295. Find median from data stream -> Problem Description