LeetCode solutions in Python
| Problem ID | Problem Name | Solution Source | Difficulty | Tag |
|---|---|---|---|---|
| 1 | Two Sum | Solution | Easy | Array, Hashing |
| 2 | Add Two Numbers | Solution | Medium | Linked List |
| 3 | Longest Substring Without Repeating Characters | Solution | Medium | Sliding Window, String |
| 4 | Median Of Two Sorted Arrays | Solution | Hard | Binary Search |
| 5 | Longest Palindromic Substring | Solution | Medium | Dynamic Programming |
| 7 | Reverse Integer | Solution | Medium | Math |
| 10 | Regular Expression Matching | Solution | Hard | Dynamic Programming |
| 11 | Container With Most Water | Solution | Medium | Array, Two Pointers |
| 15 | 3 Sum | Solution | Medium | Array, Sorting, Two Pointers |
| 17 | Letter Combinations Of A Phone Number | Solution | Medium | Backtracking |
| 19 | Remove Nth Node From End Of List | Solution | Medium | Linked List, Two Pointers |
| 20 | Valid Parentheses | Solution | Easy | Stack |
| 21 | Merge Two Sorted Lists | Solution | Easy | Linked List |
| 22 | Generate Parentheses | Solution | Medium | Stack, Backtracking |
| 23 | Merge K Sorted Lists | Solution | Hard | Linked List |
| 25 | Reverse Nodes In K Group | Solution | Hard | Linked List |
| 33 | Search In Rotated Sorted Array | Solution | Medium | Binary Search |
| 36 | Valid Sudoku | Solution | Medium | Array, Hashing |
| 39 | Combination Sum | Solution | Medium | Backtracking |
| 40 | Combination Sum II | Solution | Medium | Backtracking |
| 42 | Trapping Rain Water | Solution | Hard | Array, Two Pointers |
| 43 | Multiply Strings | Solution | Math | Math, Strings |
| 45 | Jump Game II | Solution | Medium | Backtracking |
| 46 | Permutations | Solution | Medium | Backtracking |
| 48 | Rotate Image | Solution | Medium | Math, Matrix |
| 49 | Group Anagrams | Solution | Medium | String, Hashing |
| 50 | Pow (x, n) | Solution | Medium | Math |
| 51 | N Queens | Solution | Hard | Backtracking |
| 53 | Maximum Subarray | Solution | Medium | Dynamic Programming |
| 54 | Spiral Matrix | Solution | Medium | Matrix |
| 55 | Jump Game | Solution | Medium | Greedy |
| 56 | Merge Intervals | Solution | Medium | Intervals, Array |
| 57 | Insert Interval | Solution | Medium | Intervals, Array |
| 62 | Unique Paths | Solution | Medium | Dynamic Programming |
| 66 | Plus One | Solution | Easy | Math |
| 70 | Climbing Stairs | Solution | Easy | Dynamic Programming |
| 72 | Edit Distance | Solution | Medium | Dynamic Programming |
| 73 | Set Matrix Zeroes | Solution | Medium | Matrix |
| 74 | Search A 2D Matrix | Solution | Medium | Binary Search |
| 75 | Sort Colors | Solution | Medium | Array, Two Pointers |
| 76 | Minimum Window Substring | Solution | Hard | Sliding Window |
| 78 | Subsets | Solution | Medium | Backtracking |
| 79 | Word Search | Solution | Medium | Backtracking, DFS |
| 84 | Largest Rectangle In Histogram | Solution | Hard | Stack, Monotonic Stack |
| 88 | Merge Sorted Array | Solution | Easy | Array, Two Pointers |
| 90 | Subsets II | Solution | Medium | Backtracking |
| 91 | Decode Ways | Solution | Medium | Dynamic Programming |
| 97 | Interleaving String | Solution | Medium | Dynamic Programming |
| 98 | Validate Binary Search Tree | Solution | Medium | Binary Tree, BST, DFS |
| 100 | Same Tree | Solution | Easy | Binary Tree |
| 102 | Binary Tree Level Order Traversal | Solution | Medium | Binary Tree, BFS |
| 104 | Maximum Depth Of Binary Tree | Solution | Easy | Binary Tree, Recursion |
| 105 | Construct Binary Tree From Preorder And Inorder Traversal | Solution | Medium | Binary Tree, DFS |
| 110 | Balanced Binary Tree | Solution | Easy | Binary Tree, DFS |
| 115 | Distinct Subsequences | Solution | Hard | Dynamic Programming |
| 121 | Best Time To Buy And Sell Stocks | Solution | Easy | Sliding Window |
| 124 | Binary Tree Maximum Path Sum | Solution | Hard | Binary Tree, DFS |
| 125 | Valid Palindrome | Solution | Medium | String, Two Pointers |
| 127 | Word Ladder | Solution | Hard | BFS |
| 128 | Longest Consecutive Sequence | Solution | Medium | Array, Hashing |
| 130 | Surrounded Regions | Solution | Medium | DFS |
| 131 | Palindrome Partitioning | Solution | Medium | Backtracking |
| 133 | Clone Graph | Solution | Medium | Graph, DFS |
| 134 | Gas Station | Solution | Medium | Greedy |
| 136 | Single Number | Solution | Easy | Bit Manipulation |
| 138 | Copy List With Random Pointer | Solution | Medium | Linked List, Hashing |
| 139 | Word Break | Solution | Medium | Dynamic Programming |
| 141 | Linked List Cycle | Solution | Easy | Linked List, Two Pointers |
| 143 | Reorder List | Solution | Medium | Linked List |
| 146 | LRU Cache | Solution | Medium | Design, Linked List |
| 150 | Evaluate Reverse Polish Notation | Solution | Medium | Stack |
| 152 | Maximum Product Subarray | Solution | Medium | Dynamic Programming, Two Pointers |
| 153 | Find Minimum In Rotated Sorted Array | Solution | Medium | Binary Search |
| 155 | Min Stack | Solution | Medium | Stack, Design |
| 167 | Two Sum II - Input Array Is Sorted | Solution | Medium | Array, Two Pointers |
| 190 | Reverse Bits | Solution | Easy | Bit Manipulation |
| 191 | Number Of 1 Bits | Solution | Easy | Bit Manipulation |
| 198 | House Robber | Solution | Medium | Dynamic Programming |
| 199 | Binary Tree Right Side View | Solution | Medium | Binary Tree, BFS |
| 200 | Number Of Islands | Solution | Medium | DFS |
| 202 | Happy Number | Solution | Easy | Math |
| 206 | Reverse Linked List | Solution | Easy | Linked List |
| 207 | Course Schedule | Solution | Medium | Graph, Topological Sort |
| 208 | Implement Trie | Solution | Medium | Trie, Design |
| 209 | Minimum Size Subarray Sum | Solution | Medium | Sliding Window |
| 210 | Course Schedule II | Solution | Medium | Graph, Topological Sort |
| 211 | Design Add And Search Words Data Structure | Solution | Medium | Trie, Design |
| 212 | Word Search II | Solution | Hard | Trie, Backtracking |
| 213 | House Robber II | Solution | Medium | Dynamic Programming |
| 215 | Kth Largest Element In An Array | Solution | Medium | Quick Select |
| 217 | Contains Duplicate | Solution | Easy | Array, Hashing |
| 226 | Invert Binary Tree | Solution | Easy | Binary Tree, Recursion |
| 230 | Kth Smallest Element In A BST | Solution | Medium | Binary Tree, BST, DFS |
| 235 | Lowest Common Ancestor Of A Binary Search Tree | Solution | Medium | Binary Tree, BST |
| 238 | Product Of Array Except Self | Solution | Medium | Array |
| 239 | Sliding Window Maximum | Solution | Hard | Sliding Window, Deque |
| 242 | Valid Anagram | Solution | Easy | String |
| 252 | Meeting Rooms | Solution | Easy | Intervals, Sorting |
| 253 | Meeting Rooms II | Solution | Medium | Intervals, Sorting |
| 261 | Graph Valid Tree | Solution | Medium | Graph, BFS |
| 268 | Missing Number | Solution | Easy | Math |
| 269 | Alien Dictionary | Solution | Hard | Graph, Topological Sort |
| 271 | Encode And Decode Strings | Solution | Medium | String |
| 286 | Walls And Gates | Solution | Medium | BFS |
| 287 | Find The Duplicate Number | Solution | Medium | Two Pointers |
| 295 | Find Median From Data Stream | Solution | Hard | Heap |
| 297 | Serialize And Deserialize Binary Tree | Solution | Hard | Binary Tree, BFS |
| 300 | Longest Increasing Subsequence | Solution | Medium | Dynamic Programming |
| 309 | Best Time To Buy And Sell Stocks With Cooldown | Solution | Medium | Dynamic Programming |
| 312 | Burst Balloons | Solution | Hard | Dynamic Programming |
| 322 | Coin Change | Solution | Medium | Dynamic Programming |
| 323 | Number Of Connected Components In An Undirected Graph | Solution | Medium | Union Find, Graph |
| 329 | Longest Increasing Path In A Matrix | Solution | Hard | Dynamic Programming, DFS |
| 332 | Reconstruct Itinerary | Solution | Hard | Graph, Heap |
| 338 | Counting Bits | Solution | Medium | Bit Manipulation, Dynamic Programming |
| 347 | Top K Frequent Elements | Solution | Medium | Array, Bucket Sort |
| 355 | Design Twitter | Solution | Hard | Design, Heap |
| 371 | Sum Of Two Integers | Solution | Easy | Bit Manipulation |
| 416 | Partition Equal Subset Sum | Solution | Medium | Dynamic Programming |
| 417 | Pacific Atlantic Water Flow | Solution | Medium | BFS |
| 424 | Longest Repeating Character Replacement | Solution | Medium | Sliding Window |
| 435 | Non-overlapping Intervals | Solution | Medium | Intervals, Sorting |
| 494 | Target Sum | Solution | Medium | Dynamic Programming |
| 518 | Coin Change II | Solution | Medium | Dynamic Programming |
| 543 | Diameter Of Binary Tree | Solution | Easy | Binary Tree |
| 572 | Subtree Of Another Tree | Solution | Easy | Binary Tree |
| 567 | Permutation In String | Solution | Medium | Sliding Window |
| 621 | Task Scheduler | Solution | Medium | Heap, Queue |
| 647 | Palindromic Substrings | Solution | Medium | Dynamic Programming, Two Pointers |
| 678 | Valid Parenthesis String | Solution | Medium | Greedy |
| 684 | Redundant Connection | Solution | Medium | Union Find, Graph |
| 695 | Max Area Of Island | Solution | Medium | DFS |
| 703 | Kth Largest Element In A Stream | Solution | Easy | Heap |
| 704 | Binary Search | Solution | Easy | Binary Search |
| 739 | Daily Temperatures | Solution | Medium | Stack, Monotonic Stack |
| 743 | Network Delay Time | Solution | Medium | Graph, Dijkstra's |
| 746 | Min Cost Climbing Stairs | Solution | Easy | Dynamic Programming |
| 763 | Partition Labels | Solution | Medium | Greedy |
| 778 | Swim In Rising Water | Solution | Hard | Graph, Heap |
| 787 | Cheapest Flights Within K Stops | Solution | Medium | Graph |
| 846 | Hand Of Straights | Solution | Medium | Greedy, Heap |
| 853 | Car Fleet | Solution | Medium | Stack, Monotonic Stack |
| 875 | Koko Eating Bananas | Solution | Medium | Binary Search |
| 973 | K Closest Points To Origin | Solution | Medium | Heap |
| 981 | Time Based Key Value Store | Solution | Medium | Binary Search |
| 994 | Rotting Oranges | Solution | Medium | BFS |
| 1046 | Last Stone Weight | Solution | Easy | Heap |
| 1143 | Longest Common Subsequence | Solution | Medium | Dynamic Programming |
| 1448 | Count Good Nodes In Binary Tree | Solution | Medium | Binary Tree, DFS |
| 1584 | Min Cost To Connect All Points | Solution | Medium | Graph, Prim's |
| 1851 | Minimum Interval To Include Each Query | Solution | Hard | Intervals, Heap |
| 1899 | Merge Triplets To Form Target Triplet | Solution | Medium | Greedy |
| 2013 | Detect Squares | Solution | Medium | Math, Geometry |