Array
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Array | Easy | Two Sum | Hash Map | Link | Solution |
| Array | Easy | Best Time to Buy and Sell Stock | Two Pointers | Link | Solution |
| Array | Easy | Contains Duplicate | Hash Set | Link | Solution |
| Array | Medium | Product of Array Except Self | Prefix/Suffix | Link | Solution |
| Array | Medium | Maximum Subarray | Kadane | Link | Solution |
| Array | Medium | Maximum Product Subarray | Dynamic Programming | Link | Coming Soon |
| Array | Medium | Find Minimum in Rotated Sorted Array | Binary Search | Link | Coming Soon |
| Array | Medium | Search in Rotated Sorted Array | Binary Search | Link | Solution |
| Array | Medium | 3Sum | Two Pointers | Link | Solution |
Two Pointers
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Two Pointers | Medium | Container With Most Water | Two Pointers | Link | Solution |
| Two Pointers | Easy | Valid Palindrome | Two Pointers | Link | Solution |
Binary / Bit Manipulation
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Bit | Medium | Sum of Two Integers | Bit Manipulation | Link | Solution |
| Bit | Easy | Number of 1 Bits | Bit Manipulation | Link | Solution |
| Bit | Easy | Counting Bits | Bit Manipulation | Link | Solution |
| Bit | Easy | Missing Number | Bit Manipulation | Link | Solution |
| Bit | Easy | Reverse Bits | Bit Manipulation | Link | Solution |
Backtracking
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Backtracking | Medium | Combination Sum | Backtracking | Link | Coming Soon |
| Backtracking | Medium | Subsets | Backtracking | Link | Coming Soon |
| Backtracking | Medium | Permutations | Backtracking | Link | Coming Soon |
| Backtracking | Medium | Word Search | Backtracking | Link | Coming Soon |
Dynamic Programming
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Dynamic Programming | Easy | Climbing Stairs | DP | Link | Coming Soon |
| Dynamic Programming | Medium | Coin Change | DP | Link | Coming Soon |
| Dynamic Programming | Medium | Longest Increasing Subsequence | DP + Binary Search | Link | Coming Soon |
| Dynamic Programming | Medium | Word Break | DP | Link | Solution |
| Dynamic Programming | Medium | Longest Common Subsequence | 2D DP | Link | Coming Soon |
| Dynamic Programming | Medium | House Robber | DP | Link | Coming Soon |
| Dynamic Programming | Medium | House Robber II | DP | Link | Coming Soon |
| Dynamic Programming | Medium | Decode Ways | DP | Link | Coming Soon |
| Dynamic Programming | Medium | Unique Paths | 2D DP | Link | Coming Soon |
| Dynamic Programming | Medium | Jump Game | Greedy / DP | Link | Solution |
Graph
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Graph | Medium | Number of Islands | DFS/BFS | Link | Solution |
| Graph | Medium | Clone Graph | DFS | Link | Coming Soon |
| Graph | Medium | Course Schedule | Topological Sort | Link | Coming Soon |
| Graph | Medium | Pacific Atlantic Water Flow | DFS/BFS | Link | Coming Soon |
| Graph | Medium | Longest Consecutive Sequence | Graph/Set | Link | Solution |
| Graph | Hard | Word Ladder | BFS | Link | Coming Soon |
| Graph | Medium | Graph Valid Tree | DFS/BFS/Union Find | Link | Coming Soon |
| Graph | Medium | Number of Connected Components | Union Find | Link | Coming Soon |
Heap
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Heap | Medium | Top K Frequent Elements | Heap | Link | Coming Soon |
| Heap | Hard | Find Median from Data Stream | Two Heaps | Link | Coming Soon |
| Heap | Hard | Merge k Sorted Lists | Heap | Link | Coming Soon |
Intervals
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Intervals | Medium | Insert Interval | Intervals | Link | Coming Soon |
| Intervals | Medium | Merge Intervals | Intervals | Link | Coming Soon |
| Intervals | Medium | Non-overlapping Intervals | Intervals | Link | Coming Soon |
| Intervals | Medium | Meeting Rooms | Intervals | Link | Coming Soon |
| Intervals | Medium | Meeting Rooms II | Intervals | Link | Coming Soon |
Linked List
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Linked List | Easy | Reverse Linked List | Linked List | Link | Solution |
| Linked List | Easy | Merge Two Sorted Lists | Linked List | Link | Solution |
| Linked List | Easy | Linked List Cycle | Fast & Slow Pointer | Link | Solution |
| Linked List | Medium | Remove Nth Node From End of List | Two Pointers | Link | Solution |
| Linked List | Medium | Reorder List | Two Pointers | Link | Coming Soon |
Matrix
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Matrix | Medium | Set Matrix Zeroes | Matrix | Link | Solution |
| Matrix | Medium | Spiral Matrix | Matrix | Link | Solution |
| Matrix | Medium | Rotate Image | Matrix | Link | Solution |
Sliding Window
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Sliding Window | Medium | Longest Substring Without Repeating Characters | Sliding Window | Link | Solution |
| Sliding Window | Medium | Longest Repeating Character Replacement | Sliding Window | Link | Coming Soon |
| Sliding Window | Hard | Minimum Window Substring | Sliding Window | Link | Coming Soon |
Stack
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Stack | Easy | Valid Parentheses | Stack | Link | Solution |
| Stack | Medium | Daily Temperatures | Monotonic Stack | Link | Coming Soon |
| Stack | Medium | Evaluate Reverse Polish Notation | Stack | Link | Coming Soon |
String
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| String | Easy | Valid Anagram | Hash Map | Link | Solution |
| String | Medium | Group Anagrams | Hash Map | Link | Coming Soon |
| String | Medium | Longest Palindromic Substring | DP/Two Pointers | Link | Coming Soon |
| String | Medium | Palindromic Substrings | DP/Two Pointers | Link | Solution |
| String | Medium | Encode and Decode Strings | String | Link | Coming Soon |
Trie
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Trie | Medium | Implement Trie (Prefix Tree) | Trie | Link | Coming Soon |
| Trie | Medium | Add and Search Word | Trie | Link | Coming Soon |
| Trie | Hard | Word Search II | Trie | Link | Coming Soon |
Tree
| Topic | Difficulty | Problem | Pattern | Link | Solution |
|---|---|---|---|---|---|
| Tree | Easy | Maximum Depth of Binary Tree | DFS | Link | Solution |
| Tree | Easy | Invert Binary Tree | DFS | Link | Solution |
| Tree | Easy | Same Tree | DFS | Link | Solution |
| Tree | Medium | Binary Tree Level Order Traversal | BFS | Link | Solution |
| Tree | Medium | Validate Binary Search Tree | DFS | Link | Solution |
| Tree | Medium | Lowest Common Ancestor of BST | Tree | Link | Coming Soon |
| Tree | Medium | Subtree of Another Tree | DFS | Link | Solution |
| Tree | Medium | Construct Binary Tree from Preorder and Inorder Traversal | Tree | Link | Coming Soon |
| Tree | Medium | Kth Smallest Element in a BST | DFS | Link | Solution |
| Tree | Hard | Binary Tree Maximum Path Sum | DFS | Link | Coming Soon |
| Tree | Hard | Serialize and Deserialize Binary Tree | BFS/DFS | Link | Coming Soon |