- 3Sum
- 3Sum Closest
- Container With Most Water
- Letter Combinations of a Phone Number
- Longest Common Prefix
- longest palindromic substring
- Regular Expression Matching
- reverse int
- String to Integer (atoi)
- 4Sum
- Remove Nth Node From End of List
- Generate Parentheses (backtracking)
- Merge k Sorted Lists
- Swap Nodes in Pairs
- Reverse Nodes in k-Group
- Divide Two Integers
- Substring with Concatenation of All Words
- Next Permutation
- Longest Valid Parentheses
- Search in Rotated Sorted Array
- Find First and Last Position of Element in Sorted Array
- Valid Sudoku
- Sudoku Solver
- Combination Sum
- Combination Sum2 (unique result)
- First Missing Positive
- Trapping Rain Water
- Multiply Strings
- Wildcard Matching
- Jump Game II
- Permutations
- Unique Permutations
- Rotate Image
- Group Anagrams
- N-Queens
- N-Queens II
- Spiral Matrix
- Jump Game
- Merge Intervals
- Insert Interval
- Spiral Matrix II
- Permutation Sequence
- Rotate List
- Unique Paths
- Unique Paths II
- Minimum Path Sum
- Text Justification
- Valid Number
- Simplify Path
- Simplify Path
- Edit Distance
- Set zero matrix
- Search a 2D Matrix
- Minimum Window Substring
- Combinations
- Subsets
- Word Search
- Remove Duplicates from Sorted Array II
- Search in Rotated Sorted Array II
- Remove Duplicates from Sorted List II
- Largest Rectangle in Histogram
- Maximal Rectangle
- Partition List
- Subsets II
- Decode Ways
- Reverse Linked List II
- Unique Binary Search Trees II
- Interleaving String
- Validate Binary Search Tree
- Recover Binary Search Tree
- Binary Tree Level Order Traversal
- Binary Tree Zigzag Level Order Traversal
- Construct Binary Tree from Preorder and Inorder Traversal
- Binary Tree Level Order Traversal II
- Convert Sorted List to Binary Search Tree
- Path Sum II
- Flatten Binary Tree to Linked List
- Distinct Subsequences
- Populating Next Right Pointers in Each Node
- Populating Next Right Pointers in Each Node II
- Triangle
- Best Time to Buy and Sell Stock III
- Binary Tree Maximum Path Sum
- Longest Consecutive Sequence
- Sum Root to Leaf Numbers
- Palindrome Partitioning
- cloneGraph
- Gas Station
- Candy
- copy random list
- Word Break
- detect cycle
- Reorder List
- LRU Cache
- detect cycle in graph
- Sort list