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LeetCode Questions
chubbysingh edited this page May 3, 2017
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127 revisions
https://github.com/chubbysingh/coding/tree/master/src/Leetcode
👍 - Unlocked & Done 😊 - Locked & Done 🔒 - Locked & Not Done [] - Not yet Done
| Status | Number | Title | Difficulty | Companies | Top Interview Question |
|---|---|---|---|---|---|
| 👍 | 1 | Two Sum | Easy | LinkedIn, Uber, Airbnb, Facebook | Top Interview Question |
| 👍 | 2 | Add Two Numbers | Medium | Airbnb | Top Interview Question |
| 👍 | 3 | Longest Substring Without Repeating Characters | Medium | C | Top Interview Question |
| [] | 4 | Median of Two Sorted Arrays | Hard | Top Interview Question | |
| 👍 | 5 | Longest Palindromic Substring | Medium | Top Interview Question | |
| 👍 | 6 | ZigZag Conversion | Medium | ||
| 👍 | 7 | Reverse Integer | Easy | Top Interview Question | |
| 👍 | 8 | String to Integer (atoi) | Medium | Uber | Top Interview Question |
| 👍 | 9 | Palindrome Number | Easy | ||
| 👍 | 10 | Regular Expression Matching | Hard | Google, Uber, Airbnb, Facebook | Top Interview Question |
| 👍 | 11 | Container With Most Water | Medium | Top Interview Question | |
| 👍 | 12 | Integer to Roman | Medium | ||
| 👍 | 13 | Roman to Integer | Easy | Uber, Facebook | Top Interview Question |
| 👍 | 14 | Longest Common Prefix | Easy | Top Interview Question | |
| 👍 | 15 | 3Sum | Medium | Top Interview Question | |
| 👍 | 16 | 3Sum Closest | Medium | ||
| 👍 | 17 | Letter Combinations of a Phone Number | Medium | Google, Uber, Facebook | Top Interview Question |
| 👍 | 18 | 4Sum | Medium | ||
| 👍 | 19 | Remove Nth Node From End of List | Medium | Top Interview Question | |
| 👍 | 20 | Valid Parentheses | Easy | Google, Airbnb, Facebook | Top Interview Question |
| 👍 | 21 | Merge Two Sorted Lists | Easy | Top Interview Question | |
| 👍 | 22 | Generate Parentheses | Medium | Google, Uber | Top Interview Question |
| 👍 | 23 | Merge k Sorted Lists | Hard | LinkedIn, Google, Uber, Airbnb, Facebook | Top Interview Question |
| 👍 | 24 | Swap Nodes in Pairs | Medium | Uber | |
| 👍 | 25 | Reverse Nodes in k-Group | Hard | ||
| 👍 | 26 | Remove Duplicates from Sorted Array | Easy | Top Interview Question | |
| 👍 | 27 | Remove Element | Easy | ||
| 👍 | 28 | Implement strStr() | Easy | Top Interview Question | |
| 👍 | 29 | Divide Two Integers | Medium | Top Interview Question | |
| [] | 30 | Substring with Concatenation of All Words | Hard | ||
| 👍 | 31 | Next Permutation | Medium | ||
| 👍 | 32 | Longest Valid Parentheses | Hard | ||
| 👍 | 33 | Search in Rotated Sorted Array | Medium | LinkedIn, Uber, Facebook | Top Interview Question |
| 👍 | 34 | Search for a Range | Medium | Top Interview Question | |
| 👍 | 35 | Search Insert Position | Easy | ||
| 👍 | 36 | Valid Sudoku | Medium | Uber | Top Interview Question |
| 👍 | 37 | Sudoku Solver | Hard | Uber | |
| 👍 | 38 | Count and Say | Easy | Top Interview Question | |
| 👍 | 39 | Combination Sum | Medium | Uber | |
| 👍 | 40 | Combination Sum II | Medium | ||
| 👍 | 41 | First Missing Positive | Hard | Top Interview Question | |
| 👍 | 42 | Trapping Rain Water | Hard | Top Interview Question | |
| 👍 | 43 | Multiply Strings | Medium | ||
| 👍 | 44 | Wildcard Matching | Hard | Google, Facebook | Top Interview Question |
| 👍 | 45 | Jump Game II | Hard | ||
| 👍 | 46 | Permutations | Medium | Top Interview Question | |
| 👍 | 47 | Permutations II | Medium | ||
| 👍 | 48 | Rotate Image | Medium | Top Interview Question | |
| 👍 | 49 | Group Anagrams | Medium | Uber, Facebook | Top Interview Question |
| 👍 | 50 | Pow(x, n) | Medium | LinkedIn, Google, Facebook | Top Interview Question |
| 👍 | 51 | N-Queens | Hard | ||
| 👍 | 52 | N-Queens II | Hard | ||
| 👍 | 53 | Maximum Subarray | Easy | Top Interview Question | |
| 👍 | 54 | Spiral Matrix | Medium | Google, Uber | Top Interview Question |
| 👍 | 55 | Jump Game | Medium | Top Interview Question | |
| 👍 | 56 | Merge Intervals | Medium | LinkedIn, Google, Facebook | Top Interview Question |
| [] | 57 | Insert Interval | Hard | LinkedIn, Google, Facebook | |
| 👍 | 58 | Length of Last Word | Easy | ||
| 👍 | 59 | Spiral Matrix II | Medium | ||
| 👍 | 60 | Permutation Sequence | Medium | ||
| 👍 | 61 | Rotate List | Medium | ||
| 👍 | 62 | Unique Paths | Medium | Top Interview Question | |
| 👍 | 63 | Unique Paths II | Medium | ||
| 👍 | 64 | Minimum Path Sum | Medium | ||
| [] | 65 | Valid Number | Hard | ||
| 👍 | 66 | Plus One | Easy | Top Interview Question | |
| 👍 | 67 | Add Binary | Easy | ||
| [] | 68 | Text Justification | Hard | LinkedIn, Airbnb | |
| 👍 | 69 | Sqrt(x) | Easy | Top Interview Question | |
| 👍 | 70 | Climbing Stairs | Easy | Top Interview Question | |
| 👍 | 71 | Simplify Path | Medium | ||
| 👍 | 72 | Edit Distance | Hard | ||
| 👍 | 73 | Set Matrix Zeroes | Medium | Top Interview Question | |
| 👍 | 74 | Search a 2D Matrix | Medium | ||
| 👍 | 75 | Sort Colors | Medium | Top Interview Question | |
| 👍 | 76 | Minimum Window Substring | Hard | LinkedIn, Uber, Facebook | Top Interview Question |
| 👍 | 77 | Combinations | Medium | ||
| 👍 | 78 | Subsets | Medium | Uber, Facebook | Top Interview Question |
| 👍 | 79 | Word Search | Medium | Top Interview Question | |
| 👍 | 80 | Remove Duplicates from Sorted Array II | Medium | ||
| 👍 | 81 | Search in Rotated Sorted Array II | Medium | ||
| 👍 | 82 | Remove Duplicates from Sorted List II | Medium | ||
| 👍 | 83 | Remove Duplicates from Sorted List | Easy | ||
| 👍 | 84 | Largest Rectangle in Histogram | Hard | Top Interview Question | |
| [] | 85 | Maximal Rectangle | Hard | ||
| 👍 | 86 | Partition List | Medium | ||
| [] | 87 | Scramble String | Hard | ||
| 👍 | 88 | Merge Sorted Array | Easy | Top Interview Question | |
| 👍 | 89 | Gray Code | Medium | ||
| 👍 | 90 | Subsets II | Medium | ||
| 👍 | 91 | Decode Ways | Medium | Uber, Facebook | Top Interview Question |
| 👍 | 92 | Reverse Linked List II | Medium | ||
| 👍 | 93 | Restore IP Addresses | Medium | ||
| 👍 | 94 | Binary Tree Inorder Traversal | Medium | Top Interview Question | |
| 👍 | 95 | Unique Binary Search Trees II | Medium | ||
| 👍 | 96 | Unique Binary Search Trees | Medium | ||
| [] | 97 | Interleaving String | Hard | ||
| 👍 | 98 | Validate Binary Search Tree | Medium | Top Interview Question | |
| [] | 99 | Recover Binary Search Tree | Hard | ||
| 👍 | 100 | Same Tree | Easy | ||
| 👍 | 101 | Symmetric Tree | Easy | Top Interview Question | |
| 👍 | 102 | Binary Tree Level Order Traversal | Medium | LinkedIn, Facebook | Top Interview Question |
| 👍 | 103 | Binary Tree Zigzag Level Order Traversal | Medium | Top Interview Question | |
| 👍 | 104 | Maximum Depth of Binary Tree | Easy | LinkedIn, Uber | Top Interview Question |
| 👍 | 105 | Construct Binary Tree from Preorder and Inorder Traversal | Medium | Top Interview Question | |
| 👍 | 106 | Construct Binary Tree from Inorder and Postorder Traversal | Medium | ||
| 👍 | 107 | Binary Tree Level Order Traversal II | Easy | ||
| 👍 | 108 | Convert Sorted Array to Binary Search Tree | Easy | Airbnb | Top Interview Question |
| 👍 | 109 | Convert Sorted List to Binary Search Tree | Medium | ||
| 👍 | 110 | Balanced Binary Tree | Easy | ||
| 👍 | 111 | Minimum Depth of Binary Tree | Easy | ||
| 👍 | 112 | Path Sum | Easy | ||
| 👍 | 113 | Path Sum II | Medium | ||
| 👍 | 114 | Flatten Binary Tree to Linked List | Medium | ||
| [] | 115 | Distinct Subsequences | Hard | ||
| 👍 | 116 | Populating Next Right Pointers in Each Node | Medium | Top Interview Question | |
| 👍 | 117 | Populating Next Right Pointers in Each Node II | Medium | ||
| 👍 | 118 | Pascal's Triangle | Easy | Top Interview Question | |
| 👍 | 119 | Pascal's Triangle II | Easy | ||
| 👍 | 120 | Triangle | Medium | ||
| 👍 | 121 | Best Time to Buy and Sell Stock | Easy | Uber, Facebook | Top Interview Question |
| 👍 | 122 | Best Time to Buy and Sell Stock II | Easy | Top Interview Question | |
| [] | 123 | Best Time to Buy and Sell Stock III | Hard | ||
| 👍 | 124 | Binary Tree Maximum Path Sum | Hard | Top Interview Question | |
| 👍 | 125 | Valid Palindrome | Easy | Uber, Facebook | Top Interview Question |
| [] | 126 | Word Ladder II | Hard | ||
| [] | 127 | Word Ladder | Medium | LinkedIn, Facebook | Top Interview Question |
| 👍 | 128 | Longest Consecutive Sequence | Hard | Google, Facebook | Top Interview Question |
| 👍 | 129 | Sum Root to Leaf Numbers | Medium | ||
| 👍 | 130 | Surrounded Regions | Medium | Top Interview Question | |
| 👍 | 131 | Palindrome Partitioning | Medium | Top Interview Question | |
| [] | 132 | Palindrome Partitioning II | Hard | ||
| 👍 | 133 | Clone Graph | Medium | Google, Uber, Facebook | |
| 👍 | 134 | Gas Station | Medium | Top Interview Question | |
| [] | 135 | Candy | Hard | ||
| 👍 | 136 | Single Number | Easy | Airbnb | Top Interview Question |
| 👍 | 137 | Single Number II | Medium | ||
| 👍 | 138 | Copy List with Random Pointer | Medium | Uber | Top Interview Question |
| 👍 | 139 | Word Break | Medium | Google, Uber, Facebook | Top Interview Question |
| [] | 140 | Word Break II | Hard | Google, Uber | Top Interview Question |
| 👍 | 141 | Linked List Cycle | Easy | Top Interview Question | |
| 👍 | 142 | Linked List Cycle II | Medium | ||
| 👍 | 143 | Reorder List | Medium | ||
| 👍 | 144 | Binary Tree Preorder Traversal | Medium | ||
| [] | 145 | Binary Tree Postorder Traversal | Hard | ||
| 👍 | 146 | LRU Cache | Hard | Google, Uber, Facebook | Top Interview Question |
| 👍 | 147 | Insertion Sort List | Medium | ||
| 👍 | 148 | Sort List | Medium | Top Interview Question | |
| [] | 149 | Max Points on a Line | Hard | Top Interview Question | |
| 👍 | 150 | Evaluate Reverse Polish Notation | Medium | Top Interview Question | |
| 👍 | 151 | Reverse Words in a String | Medium | ||
| 👍 | 152 | Maximum Product Subarray | Medium | Top Interview Question | |
| 👍 | 153 | Find Minimum in Rotated Sorted Array | Medium | ||
| 👍 | 154 | Find Minimum in Rotated Sorted Array II | Hard | ||
| 👍 | 155 | Min Stack | Easy | Google, Uber | Top Interview Question |
| 😊 | 156 | Binary Tree Upside Down | Medium | ||
| 😊 | 157 | Read N Characters Given Read4 | Easy | ||
| [] | 158 | Read N Characters Given Read4 II - Call multiple times | Hard | Google, Facebook | |
| [] | 159 | Longest Substring with At Most Two Distinct Characters | Hard | ||
| 👍 | 160 | Intersection of Two Linked Lists | Easy | Airbnb | Top Interview Question |
| 😊 | 161 | One Edit Distance | Medium | Uber, Facebook | |
| 👍 | 162 | Find Peak Element | Medium | Top Interview Question | |
| 😊 | 163 | Missing Ranges | Medium | Top Interview Question | |
| [] | 164 | Maximum Gap | Hard | ||
| 👍 | 165 | Compare Version Numbers | Medium | ||
| 👍 | 166 | Fraction to Recurring Decimal | Medium | Top Interview Question | |
| 👍 | 167 | Two Sum II - Input array is sorted | Easy | ||
| 👍 | 168 | Excel Sheet Column Title | Easy | ||
| 👍 | 169 | Majority Element | Easy | Top Interview Question | |
| 😊 | 170 | Two Sum III - Data structure design | Easy | ||
| 👍 | 171 | Excel Sheet Column Number | Easy | Uber | Top Interview Question |
| 👍 | 172 | Factorial Trailing Zeroes | Easy | Top Interview Question | |
| 👍 | 173 | Binary Search Tree Iterator | Medium | LinkedIn, Google, Facebook | |
| [] | 174 | Dungeon Game | Hard | ||
| 👍 | 179 | Largest Number | Medium | Top Interview Question | |
| 😊 | 186 | Reverse Words in a String II | Medium | Uber | |
| 👍 | 187 | Repeated DNA Sequences | Medium | ||
| [] | 188 | Best Time to Buy and Sell Stock IV | Hard | ||
| 👍 | 189 | Rotate Array | Easy | Top Interview Question | |
| 👍 | 190 | Reverse Bits | Easy | Airbnb | Top Interview Question |
| 👍 | 191 | Number of 1 Bits | Easy | Top Interview Question | |
| 👍 | 198 | House Robber | Easy | LinkedIn, Airbnb | Top Interview Question |
| 👍 | 199 | Binary Tree Right Side View | Medium | ||
| 👍 | 200 | Number of Islands | Medium | Google, Facebook | Top Interview Question |
| 👍 | 201 | Bitwise AND of Numbers Range | Medium | ||
| 👍 | 202 | Happy Number | Easy | Uber, Airbnb | Top Interview Question |
| 👍 | 203 | Remove Linked List Elements | Easy | ||
| 👍 | 204 | Count Primes | Easy | Top Interview Question | |
| 👍 | 205 | Isomorphic Strings | Easy | ||
| 👍 | 206 | Reverse Linked List | Easy | Uber, Facebook | Top Interview Question |
| 👍 | 207 | Course Schedule | Medium | Top Interview Question | |
| 👍 | 208 | Implement Trie (Prefix Tree) | Medium | Google, Uber, Facebook | Top Interview Question |
| 👍 | 209 | Minimum Size Subarray Sum | Medium | ||
| 👍 | 210 | Course Schedule II | Medium | Top Interview Question | |
| 👍 | 211 | Add and Search Word - Data structure design | Medium | ||
| [] | 212 | Word Search II | Hard | Google, Airbnb | Top Interview Question |
| 👍 | 213 | House Robber II | Medium | ||
| [] | 214 | Shortest Palindrome | Hard | ||
| 👍 | 215 | Kth Largest Element in an Array | Medium | Top Interview Question | |
| 👍 | 216 | Combination Sum III | Medium | ||
| 👍 | 217 | Contains Duplicate | Easy | Airbnb | Top Interview Question |
| [] | 218 | The Skyline Problem | Hard | Google, Facebook | Top Interview Question |
| 👍 | 219 | Contains Duplicate II | Easy | Airbnb | |
| 👍 | 220 | Contains Duplicate III | Medium | Airbnb | |
| 👍 | 221 | Maximal Square | Medium | Airbnb, Facebook | |
| 👍 | 222 | Count Complete Tree Nodes | Medium | ||
| 👍 | 223 | Rectangle Area | Medium | ||
| 👍 | 224 | Basic Calculator | Hard | ||
| 👍 | 225 | Implement Stack using Queues | Easy | ||
| 👍 | 226 | Invert Binary Tree | Easy | ||
| 👍 | 227 | Basic Calculator II | Medium | Top Interview Question | |
| 👍 | 228 | Summary Ranges | Medium | ||
| 👍 | 229 | Majority Element II | Medium | ||
| 👍 | 230 | Kth Smallest Element in a BST | Medium | Google, Uber | Top Interview Question |
| 👍 | 231 | Power of Two | Easy | ||
| 👍 | 232 | Implement Queue using Stacks | Easy | ||
| [] | 233 | Number of Digit One | Hard | ||
| 👍 | 234 | Palindrome Linked List | Easy | Top Interview Question | |
| 👍 | 235 | Lowest Common Ancestor of a Binary Search Tree | Easy | ||
| 👍 | 236 | Lowest Common Ancestor of a Binary Tree | Medium | LinkedIn, Facebook | Top Interview Question |
| 👍 | 237 | Delete Node in a Linked List | Easy | Top Interview Question | |
| 👍 | 238 | Product of Array Except Self | Medium | LinkedIn, Facebook | Top Interview Question |
| 👍 | 239 | Sliding Window Maximum | Hard | Top Interview Question | |
| 👍 | 240 | Search a 2D Matrix II | Medium | Top Interview Question | |
| 👍 | 241 | Different Ways to Add Parentheses | Medium | ||
| 👍 | 242 | Valid Anagram | Easy | Uber | Top Interview Question |
| 😊 | 243 | Shortest Word Distance | Easy | ||
| 😊 | 244 | Shortest Word Distance II | Medium | ||
| 😊 | 245 | Shortest Word Distance III | Medium | ||
| 😊 | 246 | Strobogrammatic Number | Easy | ||
| 😊 | 247 | Strobogrammatic Number II | Medium | ||
| [] | 248 | Strobogrammatic Number III | Hard | ||
| 😊 | 249 | Group Shifted Strings | Medium | Google, Uber | |
| 😊 | 250 | Count Univalue Subtrees | Medium | ||
| 😊 | 251 | Flatten 2D Vector | Medium | Google, Airbnb | Top Interview Question |
| 😊 | 252 | Meeting Rooms | Easy | ||
| 😊 | 253 | Meeting Rooms II | Medium | Google, Facebook | Top Interview Question |
| 😊 | 254 | Factor Combinations | Medium | LinkedIn, Uber | |
| 😊 | 255 | Verify Preorder Sequence in Binary Search Tree | Medium | ||
| 😊 | 256 | Paint House | Easy | ||
| 👍 | 257 | Binary Tree Paths | Easy | Google, Facebook | |
| 👍 | 258 | Add Digits | Easy | ||
| 😊 | 259 | 3Sum Smaller | Medium | ||
| 👍 | 260 | Single Number III | Medium | ||
| 😊 | 261 | Graph Valid Tree | Medium | Google, Facebook | |
| 👍 | 263 | Ugly Number | Easy | ||
| 👍 | 264 | Ugly Number II | Medium | ||
| [] | 265 | Paint House II | Hard | ||
| 😊 | 266 | Palindrome Permutation | Easy | Google, Uber | |
| 😊 | 267 | Palindrome Permutation II | Medium | ||
| 👍 | 268 | Missing Number | Easy | Top Interview Question | |
| [] | 269 | Alien Dictionary | Hard | Google, Airbnb, Facebook | Top Interview Question |
| 😊 | 270 | Closest Binary Search Tree Value | Easy | ||
| 😊 | 271 | Encode and Decode Strings | Medium | ||
| [] | 272 | Closest Binary Search Tree Value II | Hard | ||
| [] | 273 | Integer to English Words | Hard | ||
| 👍 | 274 | H-Index | Medium | Google, Facebook | |
| 👍 | 275 | H-Index II | Medium | ||
| 😊 | 276 | Paint Fence | Easy | ||
| 😊 | 277 | Find the Celebrity | Medium | LinkedIn, Facebook | Top Interview Question |
| 👍 | 278 | First Bad Version | Easy | ||
| 👍 | 279 | Perfect Squares | Medium | Top Interview Question | |
| 😊 | 280 | Wiggle Sort | Medium | ||
| 😊 | 281 | Zigzag Iterator | Medium | ||
| 👍 | 282 | Expression Add Operators | Hard | Google, Facebook | |
| 👍 | 283 | Move Zeroes | Easy | Top Interview Question | |
| 👍 | 284 | Peeking Iterator | Medium | ||
| 😊 | 285 | Inorder Successor in BST | Medium | ||
| 😊 | 286 | Walls and Gates | Medium | Google, Facebook | |
| 👍 | 287 | Find the Duplicate Number | Medium | Top Interview Question | |
| 😊 | 288 | Unique Word Abbreviation | Medium | ||
| 👍 | 289 | Game of Life | Medium | Top Interview Question | |
| 👍 | 290 | Word Pattern | Easy | Uber | |
| [] | 291 | Word Pattern II | Hard | Uber | |
| 👍 | 292 | Nim Game | Easy | ||
| 😊 | 293 | Flip Game | Easy | ||
| 😊 | 294 | Flip Game II | Medium | ||
| 👍 | 295 | Find Median from Data Stream | Hard | Top Interview Question | |
| [] | 296 | Best Meeting Point | Hard | ||
| 👍 | 297 | Serialize and Deserialize Binary Tree | Hard | LinkedIn, Google, Uber, Facebook | Top Interview Question |
| 😊 | 298 | Binary Tree Longest Consecutive Sequence | Medium | ||
| 👍 | 299 | Bulls and Cows | Medium | ||
| 👍 | 300 | Longest Increasing Subsequence | Medium | Top Interview Question | |
| [] | 301 | Remove Invalid Parentheses | Hard | ||
| [] | 302 | Smallest Rectangle Enclosing Black Pixels | Hard | ||
| 👍 | 303 | Range Sum Query - Immutable | Easy | ||
| 👍 | 304 | Range Sum Query 2D - Immutable | Medium | ||
| [] | 305 | Number of Islands II | Hard | ||
| [] | 306 | Additive Number | Medium | ||
| [] | 307 | Range Sum Query - Mutable | Medium | ||
| [] | 308 | Range Sum Query 2D - Mutable | Hard | Top Interview Question | |
| 👍 | 309 | Best Time to Buy and Sell Stock with Cooldown | Medium | ||
| [] | 310 | Minimum Height Trees | Medium | ||
| 😊 | 311 | Sparse Matrix Multiplication | Medium | LinkedIn, Facebook | |
| [] | 312 | Burst Balloons | Hard | ||
| 👍 | 313 | Super Ugly Number | Medium | ||
| 😊 | 314 | Binary Tree Vertical Order Traversal | Medium | Google, Facebook | |
| 👍 | 315 | Count of Smaller Numbers After Self | Hard | Top Interview Question | |
| [] | 316 | Remove Duplicate Letters | Hard | ||
| [] | 317 | Shortest Distance from All Buildings | Hard | ||
| 👍 | 318 | Maximum Product of Word Lengths | Medium | ||
| 👍 | 319 | Bulb Switcher | Medium | ||
| 😊 | 320 | Generalized Abbreviation | Medium | ||
| [] | 321 | Create Maximum Number | Hard | ||
| 👍 | 322 | Coin Change | Medium | Top Interview Question | |
| 😊 | 323 | Number of Connected Components in an Undirected Graph | Medium | ||
| 👍 | 324 | Wiggle Sort II | Medium | Top Interview Question | |
| 😊 | 325 | Maximum Size Subarray Sum Equals k | Medium | ||
| 👍 | 326 | Power of Three | Easy | Top Interview Question | |
| [] | 327 | Count of Range Sum | Hard | ||
| 👍 | 328 | Odd Even Linked List | Medium | Top Interview Question | |
| 👍 | 329 | Longest Increasing Path in a Matrix | Hard | Top Interview Question | |
| [] | 330 | Patching Array | Hard | ||
| 👍 | 331 | Verify Preorder Serialization of a Binary Tree | Medium | ||
| 👍 | 332 | Reconstruct Itinerary | Medium | ||
| 😊 | 333 | Largest BST Subtree | Medium | ||
| 👍 | 334 | Increasing Triplet Subsequence | Medium | Top Interview Question | |
| [] | 335 | Self Crossing | Hard | ||
| [] | 336 | Palindrome Pairs | Hard | Google, Airbnb | |
| 👍 | 337 | House Robber III | Medium | Uber | |
| 👍 | 338 | Counting Bits | Medium | ||
| 😊 | 339 | Nested List Weight Sum | Easy | ||
| [] | 340 | Longest Substring with At Most K Distinct Characters | Hard | Top Interview Question | |
| 👍 | 341 | Flatten Nested List Iterator | Medium | Top Interview Question | |
| 👍 | 342 | Power of Four | Easy | ||
| 👍 | 343 | Integer Break | Medium | ||
| 👍 | 344 | Reverse String | Easy | C | Top Interview Question |
| 👍 | 345 | Reverse Vowels of a String | Easy | ||
| 😊 | 346 | Moving Average from Data Stream | Easy | ||
| 👍 | 347 | Top K Frequent Elements | Medium | C | Top Interview Question |
| 😊 | 348 | Design Tic-Tac-Toe | Medium | C | Top Interview Question |
| 👍 | 349 | Intersection of Two Arrays | Easy | ||
| 👍 | 350 | Intersection of Two Arrays II | Easy | C | Top Interview Question |
| 😊 | 351 | Android Unlock Patterns | Medium | ||
| [] | 352 | Data Stream as Disjoint Intervals | Hard | ||
| 😊 | 353 | Design Snake Game | Medium | ||
| [] | 354 | Russian Doll Envelopes | Hard | ||
| 👍 | 355 | Design Twitter | Medium | ||
| 😊 | 356 | Line Reflection | Medium | ||
| 👍 | 357 | Count Numbers with Unique Digits | Medium | ||
| [] | 358 | Rearrange String k Distance Apart | Hard | ||
| 😊 | 359 | Logger Rate Limiter | Easy | ||
| 😊 | 360 | Sort Transformed Array | Medium | ||
| 🔒 | 361 | Bomb Enemy | Medium | ||
| 😊 | 362 | Design Hit Counter | Medium | ||
| [] | 363 | Max Sum of Rectangle No Larger Than K | Hard | ||
| 😊 | 364 | Nested List Weight Sum II | Medium | ||
| 👍 | 365 | Water and Jug Problem | Medium | ||
| 😊 | 366 | Find Leaves of Binary Tree | Medium | ||
| 👍 | 367 | Valid Perfect Square | Easy | ||
| 👍 | 368 | Largest Divisible Subset | Medium | ||
| 😊 | 369 | Plus One Linked List | Medium | ||
| 😊 | 370 | Range Addition | Medium | ||
| 👍 | 371 | Sum of Two Integers | Easy | C | Top Interview Question |
| 👍 | 372 | Super Pow | Medium | ||
| 👍 | 373 | Find K Pairs with Smallest Sums | Medium | ||
| 👍 | 374 | Guess Number Higher or Lower | Easy | ||
| 👍 | 375 | Guess Number Higher or Lower II | Medium | ||
| 👍 | 376 | Wiggle Subsequence | Medium | ||
| 👍 | 377 | Combination Sum IV | Medium | ||
| 👍 | 378 | Kth Smallest Element in a Sorted Matrix | Medium | C | Top Interview Question |
| 😊 | 379 | Design Phone Directory | Medium | ||
| 👍 | 380 | Insert Delete GetRandom O(1) | Medium | C | Top Interview Question |
| [] | 381 | Insert Delete GetRandom O(1) - Duplicates allowed | Hard | ||
| 👍 | 382 | Linked List Random Node | Medium | ||
| 👍 | 383 | Ransom Note | Easy | ||
| 👍 | 384 | Shuffle an Array | Medium | C | Top Interview Question |
| 👍 | 385 | Mini Parser | Medium | ||
| [] | 386 | Lexicographical Numbers | Medium | ||
| 👍 | 387 | First Unique Character in a String | Easy | C | Top Interview Question |
| 👍 | 388 | Longest Absolute File Path | Medium | ||
| 👍 | 389 | Find the Difference | Easy | ||
| 👍 | 390 | Elimination Game | Medium | ||
| [] | 391 | Perfect Rectangle | Hard | ||
| 👍 | 392 | Is Subsequence | Medium | ||
| [] | 393 | UTF-8 Validation | Medium | ||
| 👍 | 394 | Decode String | Medium | ||
| 👍 | 395 | Longest Substring with At Least K Repeating Characters | Medium | C | Top Interview Question |
| 👍 | 396 | Rotate Function | Medium | ||
| 👍 | 397 | Integer Replacement | Medium | ||
| 👍 | 398 | Random Pick Index | Medium | ||
| [] | 399 | Evaluate Division | Medium | ||
| 👍 | 400 | Nth Digit | Easy | ||
| 👍 | 401 | Binary Watch | Easy | ||
| [] | 402 | Remove K Digits | Medium | ||
| [] | 403 | Frog Jump | Hard | ||
| 👍 | 404 | Sum of Left Leaves | Easy | ||
| 👍 | 405 | Convert a Number to Hexadecimal | Easy | ||
| 👍 | 406 | Queue Reconstruction by Height | Medium | ||
| [] | 407 | Trapping Rain Water II | Hard | ||
| 😊 | 408 | Valid Word Abbreviation | Easy | ||
| 👍 | 409 | Longest Palindrome | Easy | ||
| [] | 410 | Split Array Largest Sum | Hard | ||
| [] | 411 | Minimum Unique Word Abbreviation | Hard | ||
| 👍 | 412 | Fizz Buzz | Easy | C | Top Interview Question |
| 👍 | 413 | Arithmetic Slices | Medium | ||
| 👍 | 414 | Third Maximum Number | Easy | ||
| 👍 | 415 | Add Strings | Easy | ||
| 👍 | 416 | Partition Equal Subset Sum | Medium | ||
| [] | 417 | Pacific Atlantic Water Flow | Medium | ||
| 🔒 | 418 | Sentence Screen Fitting | Medium | ||
| 👍 | 419 | Battleships in a Board | Medium | ||
| [] | 420 | Strong Password Checker | Hard | ||
| [] | 421 | Maximum XOR of Two Numbers in an Array | Medium | ||
| 😊 | 422 | Valid Word Square | Easy | ||
| 👍 | 423 | Reconstruct Original Digits from English | Medium | ||
| [] | 424 | Longest Repeating Character Replacement | Medium | ||
| [] | 425 | Word Squares | Hard | ||
| [] | 432 | All O`one Data Structure | Hard | ||
| 👍 | 434 | Number of Segments in a String | Easy | ||
| 👍 | 435 | Non-overlapping Intervals | Medium | ||
| [] | 436 | Find Right Interval | Medium | ||
| [] | 437 | Path Sum III | Easy | ||
| [] | 438 | Find All Anagrams in a String | Easy | ||
| 😊 | 439 | Ternary Expression Parser | Medium | ||
| [] | 440 | K-th Smallest in Lexicographical Order | Hard | ||
| 👍 | 441 | Arranging Coins | Easy | ||
| 👍 | 442 | Find All Duplicates in an Array | Medium | ||
| 🔒 | 444 | Sequence Reconstruction | Medium | ||
| 👍 | 445 | Add Two Numbers II | Medium | ||
| [] | 446 | Arithmetic Slices II - Subsequence | Hard | ||
| [] | 447 | Number of Boomerangs | Easy | ||
| 👍 | 448 | Find All Numbers Disappeared in an Array | Easy | ||
| [] | 449 | Serialize and Deserialize BST | Medium | ||
| [] | 450 | Delete Node in a BST | Medium | ||
| [] | 451 | Sort Characters By Frequency | Medium | ||
| [] | 452 | Minimum Number of Arrows to Burst Balloons | Medium | ||
| 👍 | 453 | Minimum Moves to Equal Array Elements | Easy | ||
| 👍 | 454 | 4Sum II | Medium | C | Top Interview Question |
| 👍 | 455 | Assign Cookies | Easy | ||
| [] | 456 | 132 Pattern | Medium | ||
| [] | 459 | Repeated Substring Pattern | Easy | ||
| [] | 460 | LFU Cache | Hard | ||
| 👍 | 461 | Hamming Distance | Easy | ||
| 👍 | 462 | Minimum Moves to Equal Array Elements II | Medium | ||
| 👍 | 463 | Island Perimeter | Easy | ||
| [] | 464 | Can I Win | Medium | ||
| [] | 465 | Optimal Account Balancing | Hard | ||
| [] | 466 | Count The Repetitions | Hard | ||
| 👍 | 467 | Unique Substrings in Wraparound String | Medium | ||
| [] | 468 | Validate IP Address | Medium | ||
| 🔒 | 469 | Convex Polygon | Medium | ||
| [] | 471 | Encode String with Shortest Length | Hard | ||
| [] | 472 | Concatenated Words | Hard | ||
| [] | 473 | Matchsticks to Square | Medium | ||
| 👍 | 474 | Ones and Zeroes | Medium | ||
| [] | 475 | Heaters | Easy | ||
| 👍 | 476 | Number Complement | Easy | ||
| 👍 | 477 | Total Hamming Distance | Medium | ||
| [] | 480 | Sliding Window Median | Hard | ||
| 👍 | 481 | Magical String | Medium | ||
| 👍 | 482 | License Key Formatting | Medium | ||
| [] | 483 | Smallest Good Base | Hard | ||
| 🔒 | 484 | Find Permutation | Medium | ||
| 👍 | 485 | Max Consecutive Ones | Easy | ||
| [] | 486 | Predict the Winner | Medium | ||
| 🔒 | 487 | Max Consecutive Ones II | Medium | ||
| [] | 488 | Zuma Game | Hard | ||
| 😊 | 490 | The Maze | Medium | ||
| [] | 491 | Increasing Subsequences | Medium | ||
| 👍 | 492 | Construct the Rectangle | Easy | ||
| [] | 493 | Reverse Pairs | Hard | ||
| 👍 | 494 | Target Sum | Medium | ||
| [] | 495 | Teemo Attacking | Medium | ||
| 👍 | 496 | Next Greater Element I | Easy | ||
| [] | 498 | Diagonal Traverse | Medium | ||
| [] | 499 | The Maze III | Hard | ||
| 👍 | 500 | Keyboard_Row | Easy | ||
| [] | 501 | Find Mode in Binary Search Tree | Easy | ||
| [] | 502 | IPO | Hard | ||
| 👍 | 503 | Next Greater Element II | Medium | ||
| 👍 | 504 | Base 7 | Easy | ||
| 🔒 | 505 | The Maze II | Medium | ||
| [] | 506 | Relative Ranks | Easy | ||
| [] | 508 | Most Frequent Subtree Sum | Medium | ||
| 👍 | 513 | Find Bottom Left Tree Value | Medium | ||
| [] | 514 | Freedom Trail | Hard | ||
| 👍 | 515 | Find Largest Value in Each Tree Row | Medium | ||
| 👍 | 516 | Longest Palindromic Subsequence | Medium | ||
| [] | 517 | Super Washing Machines | Hard | ||
| 👍 | 520 | Detect Capital | Easy | ||
| 👍 | 523 | Continuous Subarray Sum | Medium | ||
| 👍 | 524 | Longest Word in Dictionary through Deleting | Medium | ||
| [] | 525 | Contiguous Array | Medium | ||
| [] | 526 | Beautiful Arrangement | Medium | ||
| [] | 527 | Word Abbreviation | Hard | ||
| [] | 529 | Minesweeper | Medium | ||
| 👍 | 530 | Minimum Absolute Difference in BST | Easy | ||
| 🔒 | 531 | Lonely Pixel I | Medium | ||
| [] | 532 | K-diff Pairs in an Array | Easy | ||
| 🔒 | 533 | Lonely Pixel II | Medium | ||
| 👍 | 535 | Encode and Decode TinyURL | Medium | ||
| 🔒 | 536 | Construct Binary Tree from String | Medium | ||
| 👍 | 537 | Complex Number Multiplication | Medium | ||
| [] | 538 | Convert BST to Greater Tree | Medium | ||
| [] | 539 | Minimum Time Difference | Medium | ||
| [] | 541 | Reverse String II | Easy | ||
| [] | 542 | 01 Matrix | Medium | ||
| 👍 | 543 | Diameter of Binary Tree | Easy | ||
| 🔒 | 544 | Output Contest Matches | Medium | ||
| 😊 | 545 | Boundary of Binary Tree | Medium | ||
| 🔒 | 548 | Split Array with Equal Sum | Medium | ||
| 🔒 | 549 | Binary Tree Longest Consecutive Sequence II | Medium | ||
| 🔒 | 555 | Split Concatenated Strings | Medium | ||
| 🔒 | 562 | Longest Line of Consecutive One in Matrix | Medium |