- 3. Longest Substring Without Repeating Characters
- 5. Longest Palindromic Substring
- 9. Palindrome Number
- 15. 3sum
- 16. 3Sum Closest
- 17. Letter Combinations of a Phone Number
- 18. 4Sum
- 19. Remove Nth Node From End of List
- 22. Generate Parentheses
- 26. Remove Duplicates from Sorted Array
- 27. Remove Element
- 31. Next Permutation
- 32. Longest Valid Parentheses
- 33. Search in Rotated Sorted Array
- 34. Search for a Range
- 39. Combination Sum
- 40. Combination Sum II
- 46. Permutations
- 47. Permutations II
- 48. Rotate Image
- 50. Pow(x, n)
- 53. Maximum Subarray
- 55. Jump Game
- 60. Permutation Sequence
- 62. Unique Paths
- 63. Unique Paths II
- 64. Minimum Path Sum
- 69. Sqrt(x)
- 70. Climbing Stairs
- 72. Edit Distance
- 73. Set Matrix Zeroes
- 75. Sort Colors
- 77. Combinations
- 79. Word Search
- 80. Remove Duplicates from Sorted Array II
- 81. Search in Rotated Sorted Array II
- 82. Remove Duplicates from Sorted List II
- 90. Subsets II
- 91. Decode Ways
- 93. Restore IP Addresses
- 94. Binary Tree Inorder Traversal
- 95. Unique Binary Search Trees II
- 96. Unique Binary Search Trees
- 98. Validate Binary Search Tree
- 99. recover Binary Search Tree
- 100. Same Tree
- 101. Symmetric Tree
- 102. Binary Tree Level Order Traversal
- 104. Maximum Depth of Binary Tree
- 105. Construct Binary Tree from Preorder and Inorder Traversal
- 108. Convert Sorted Array to Binary Search Tree
- 110. Balanced Binary Tree
- 111. Minimum Depth of Binary Tree
- 112. Path Sum
- 113. Path Sum II
- 114. Flatten Binary Tree to Linked List
- 118. Pascal's Triangle
- 119. Pascal's Triangle II
- 120. Triangle
- 121. Best Time to Buy and Sell Stock
- 122. Best Time to Buy and Sell Stock II
- 123. Best Time to Buy and Sell Stock III
- 129. Sum Root to Leaf Numbers
- 131. Palindrome Partitioning
- 134. Gas Station
- 138. Copy List with Random Pointer
- 139. Word Break
- 140. Word Break II
- 141. Linked List Cycle
- 144. Binary Tree Preorder Traversal
- 145. Binary Tree Postorder Traversal
- 152. Maximum Product Subarray
- 153. Find Minimum in Rotated Sorted Array
- 154. Find Minimum in Rotated Sorted Array II
- 188. Best Time to Buy and Sell Stock IV
- 204. Count Primes
- 209. Minimum Size Subarray Sum
- 215. Kth Largest Element in an Array
- 220. Contains Duplicate III
- 221. Maximal Square
- 235. Lowest Common Ancestor of a Binary Search Tree
- 236. Lowest Common Ancestor of a Binary Tree
- 239. Sliding Window Maximum
- 264. Ugly Number II
- 300. Longest Increasing Subsequence