Top Interview 150
Master the essential data structures and algorithms.
| Status | Problem | Difficulty |
|---|---|---|
| Array / String | ||
| Merge Sorted Array | Easy | |
| Remove Element | Easy | |
| Remove Duplicates from Sorted Array | Easy | |
| Remove Duplicates from Sorted Array II | Medium | |
| Majority Element | Easy | |
| Rotate Array | Medium | |
| Best Time to Buy and Sell Stock | Easy | |
| Best Time to Buy and Sell Stock II | Medium | |
| Jump Game | Medium | |
| Jump Game II | Medium | |
| H-Index | Medium | |
| Insert Delete GetRandom O(1) | Medium | |
| Product of Array Except Self | Medium | |
| Gas Station | Medium | |
| Candy | Hard | |
| Trapping Rain Water | Hard | |
| Roman to Integer | Easy | |
| Integer to Roman | Medium | |
| Length of Last Word | Easy | |
| Longest Common Prefix | Easy | |
| Reverse Words in a String | Medium | |
| Zigzag Conversion | Medium | |
| Find the Index of the First Occurrence in a String | Easy | |
| Text Justification | Hard | |
| Two Pointers | ||
| Valid Palindrome | Easy | |
| Is Subsequence | Easy | |
| Two Sum II - Input Array Is Sorted | Medium | |
| Container With Most Water | Medium | |
| 3Sum | Medium | |
| Sliding Window | ||
| Minimum Size Subarray Sum | Medium | |
| Longest Substring Without Repeating Characters | Medium | |
| Substring with Concatenation of All Words | Hard | |
| Minimum Window Substring | Hard | |
| Matrix | ||
| Valid Sudoku | Medium | |
| Spiral Matrix | Medium | |
| Rotate Image | Medium | |
| Set Matrix Zeroes | Medium | |
| Game of Life | Medium | |
| Hashmap | ||
| Ransom Note | Easy | |
| Isomorphic Strings | Easy | |
| Word Pattern | Easy | |
| Valid Anagram | Easy | |
| Group Anagrams | Medium | |
| Two Sum | Easy | |
| Happy Number | Easy | |
| Contains Duplicate II | Easy | |
| Longest Consecutive Sequence | Medium | |
| Intervals | ||
| Summary Ranges | Easy | |
| Merge Intervals | Medium | |
| Insert Interval | Medium | |
| Minimum Number of Arrows to Burst Balloons | Medium | |
| Stack | ||
| Valid Parentheses | Easy | |
| Simplify Path | Medium | |
| Min Stack | Medium | |
| Evaluate Reverse Polish Notation | Medium | |
| Basic Calculator | Hard | |
| Linked List | ||
| Linked List Cycle | Easy | |
| Add Two Numbers | Medium | |
| Merge Two Sorted Lists | Easy | |
| Copy List with Random Pointer | Medium | |
| Reverse Linked List II | Medium | |
| Reverse Nodes in k-Group | Hard | |
| Remove Nth Node From End of List | Medium | |
| Remove Duplicates from Sorted List II | Medium | |
| Rotate List | Medium | |
| Partition List | Medium | |
| LRU Cache | Medium | |
| Binary Tree General | ||
| Maximum Depth of Binary Tree | Easy | |
| Same Tree | Easy | |
| Invert Binary Tree | Easy | |
| Symmetric Tree | Easy | |
| Construct Binary Tree from Preorder and Inorder Traversal | Medium | |
| Construct Binary Tree from Inorder and Postorder Traversal | Medium | |
| Populating Next Right Pointers in Each Node II | Medium | |
| Flatten Binary Tree to Linked List | Medium | |
| Path Sum | Easy | |
| Sum Root to Leaf Numbers | Medium | |
| Binary Tree Maximum Path Sum | Hard | |
| Binary Search Tree Iterator | Medium | |
| Count Complete Tree Nodes | Easy | |
| Binary Tree BFS | ||
| Binary Tree Right Side View | Medium | |
| Average of Levels in Binary Tree | Easy | |
| Binary Tree Level Order Traversal | Medium | |
| Binary Tree Zigzag Level Order Traversal | Medium | |
| Binary Search Tree | ||
| Minimum Absolute Difference in BST | Easy | |
| Kth Smallest Element in a BST | Medium | |
| Validate Binary Search Tree | Medium | |
| Graph General | ||
| Number of Islands | Medium | |
| Surrounded Regions | Medium | |
| Clone Graph | Medium | |
| Evaluate Division | Medium | |
| Course Schedule | Medium | |
| Course Schedule II | Medium | |
| Graph BFS | ||
| Snakes and Ladders | Medium | |
| Minimum Genetic Mutation | Medium | |
| Word Ladder | Hard | |
| Trie | ||
| Implement Trie (Prefix Tree) | Medium | |
| Design Add and Search Words Data Structure | Medium | |
| Word Search II | Hard | |
| Backtracking | ||
| Letter Combinations of a Phone Number | Medium | |
| Combinations | Medium | |
| Permutations | Medium | |
| Combination Sum | Medium | |
| N-Queens II | Hard | |
| Generate Parentheses | Medium | |
| Word Search | Medium | |
| Divide & Conquer | ||
| Convert Sorted Array to Binary Search Tree | Easy | |
| Sort List | Medium | |
| Construct Quad Tree | Medium | |
| Merge k Sorted Lists | Hard | |
| Kadane's Algorithm | ||
| Maximum Subarray | Medium | |
| Maximum Sum Circular Subarray | Medium | |
| Binary Search | ||
| Search Insert Position | Easy | |
| Search a 2D Matrix | Medium | |
| Find Peak Element | Medium | |
| Search in Rotated Sorted Array | Medium | |
| Find First and Last Position of Element in Sorted Array | Medium | |
| Find Minimum in Rotated Sorted Array | Medium | |
| Median of Two Sorted Arrays | Hard | |
| Heap | ||
| Kth Largest Element in an Array | Medium | |
| IPO | Hard | |
| Find K Pairs with Smallest Sums | Medium | |
| Find Median from Data Stream | Hard | |
| Bit Manipulation | ||
| Add Binary | Easy | |
| Reverse Bits | Easy | |
| Number of 1 Bits | Easy | |
| Single Number | Easy | |
| Single Number II | Medium | |
| Bitwise AND of Numbers Range | Medium | |
| Math | ||
| Palindrome Number | Easy | |
| Plus One | Easy | |
| Factorial Trailing Zeroes | Medium | |
| Sqrt(x) | Easy | |
| Pow(x, n) | Medium | |
| Max Points on a Line | Hard | |
| 1D DP | ||
| Climbing Stairs | Easy | |
| House Robber | Medium | |
| Word Break | Medium | |
| Coin Change | Medium | |
| Longest Increasing Subsequence | Medium | |
| Multidimensional DP | ||
| Triangle | Medium | |
| Minimum Path Sum | Medium | |
| Longest Palindromic Substring | Medium | |
| Interleaving String | Medium | |
| Edit Distance | Medium | |
| Best Time to Buy and Sell Stock III | Hard | |
| Best Time to Buy and Sell Stock IV | Hard | |
| Maximal Square | Medium | |