Author: github.com/lzl124631x
My C++ Code for LeetCode OJ.
Please give this repo a ⭐ if it inspires you. Thanks. 😊
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| # | Title | Difficulty | Solution |
|---|---|---|---|
| 1 | Two Sum | Easy | Solution |
| 2 | Add Two Numbers | Medium | Solution |
| 3 | Longest Substring Without Repeating Characters | Medium | Solution |
| 4 | Median of Two Sorted Arrays | Hard | Solution |
| 5 | Longest Palindromic Substring | Medium | Solution |
| 6 | ZigZag Conversion | Medium | Solution |
| 7 | Reverse Integer | Easy | Solution |
| 8 | String to Integer (atoi) | Medium | Solution |
| 9 | Palindrome Number | Easy | Solution |
| 10 | Regular Expression Matching | Hard | Solution |
| 11 | Container With Most Water | Medium | Solution |
| 12 | Integer to Roman | Solution | |
| 13 | Roman to Integer | Solution | |
| 14 | Longest Common Prefix | Solution | |
| 15 | 3Sum | Medium | Solution |
| 16 | 3Sum Closest | Medium | Solution |
| 17 | Letter Combinations of a Phone Number | Medium | Solution |
| 18 | 4Sum | Solution | |
| 19 | Remove Nth Node From End of List | Solution | |
| 20 | Valid Parentheses | Solution | |
| 21 | Merge Two Sorted Lists | Easy | Solution |
| 22 | Generate Parentheses | Medium | Solution |
| 23 | Merge k Sorted Lists | Hard | Solution |
| 24 | Swap Nodes in Pairs | Solution | |
| 25 | Reverse Nodes in k-Group | Solution | |
| 26 | Remove Duplicates from Sorted Array | Solution | |
| 27 | Remove Element | Solution | |
| 28 | Implement strStr() | Easy | Solution |
| 29 | Divide Two Integers | Medium | Solution |
| 30 | Substring with Concatenation of All Words | Solution | |
| 31 | Next Permutation | Medium | Solution |
| 32 | Longest Valid Parentheses | Hard | Solution |
| 33 | Search in Rotated Sorted Array | Medium | Solution |
| 34 | Search for a Range | Solution | |
| 35 | Search Insert Position | Easy | Solution |
| 36 | Valid Sudoku | Solution | |
| 38 | Count and Say | Solution | |
| 39 | Combination Sum | Medium | Solution |
| 40 | Combination Sum II | Medium | Solution |
| 41 | First Missing Positive | Hard | Solution |
| 42 | Trapping Rain Water | Hard | Solution |
| 43 | Multiply Strings | Solution | |
| 44 | Wildcard Matching | Hard | Solution |
| 45 | Jump Game II | Hard | Solution |
| 46 | Permutations | Medium | Solution |
| 47 | Permutations II | Medium | Solution |
| 48 | Rotate Image | Solution | |
| 49 | Group Anagrams | Medium | Solution |
| 50 | Pow(x, n) | Medium | Solution |
| 53 | Maximum Subarray | Easy | Solution |
| 54 | Spiral Matrix | Medium | Solution |
| 55 | Jump Game | Medium | Solution |
| 58 | Length of Last Word | Solution | |
| 59 | Spiral Matrix II | Solution | |
| 60 | Permutation Sequence | Medium | Solution |
| 61 | Rotate List | Solution | |
| 62 | Unique Paths | Medium | Solution |
| 63 | Unique Paths II | Medium | Solution |
| 64 | Minimum Path Sum | Medium | Solution |
| 65 | Valid Number | Hard | Solution |
| 66 | Plus One | Easy | Solution |
| 67 | Add Binary | Easy | Solution |
| 69 | Sqrt(x) | Solution | |
| 70 | Climbing Stairs | Easy | Solution |
| 71 | Simplify Path | Solution | |
| 72 | Edit Distance | Hard | Solution |
| 74 | Search a 2D Matrix | Solution | |
| 75 | Sort Colors | Medium | Solution |
| 76 | Minimum Window Substring | Hard | Solution |
| 77 | Combinations | Medium | Solution |
| 78 | Subsets | Medium | Solution |
| 79 | Word Search | Medium | Solution |
| 80 | Remove Duplicates from Sorted Array II | Solution | |
| 81 | Search in Rotated Sorted Array II | Medium | Solution |
| 82 | Remove Duplicates from Sorted List II | Solution | |
| 83 | Remove Duplicates from Sorted List | Solution | |
| 84 | Largest Rectangle in Histogram | Hard | Solution |
| 85 | Maximal Rectangle | Hard | Solution |
| 86 | Partition List | Medium | Solution |
| 87 | Scramble String | Hard | Solution |
| 88 | Merge Sorted Array | Solution | |
| 89 | Gray Code | Medium | Solution |
| 90 | Subsets II | Medium | Solution |
| 91 | Decode Ways | Medium | Solution |
| 92 | Reverse Linked List II | Solution | |
| 93 | Restore IP Addresses | Solution | |
| 94 | Binary Tree Inorder Traversal | Medium | Solution |
| 95 | Unique Binary Search Trees II | Medium | Solution |
| 96 | Unique Binary Search Trees | Medium | Solution |
| 97 | Interleaving String | Hard | Solution |
| 98 | Validate Binary Search Tree | Medium | Solution |
| 99 | Recover Binary Search Tree | Hard | Solution |
| 100 | Same Tree | Easy | Solution |
| 101 | Symmetric Tree | Solution | |
| 102 | Binary Tree Level Order Traversal | Medium | Solution |
| 103 | Binary Tree Zigzag Level Order Traversal | Medium | Solution |
| 104 | Maximum Depth of Binary Tree | Easy | Solution |
| 106 | Construct Binary Tree from Inorder and Postorder Traversal | Solution | |
| 107 | Binary Tree Level Order Traversal II | Easy | Solution |
| 108 | Convert Sorted Array to Binary Search Tree | Solution | |
| 109 | Convert Sorted List to Binary Search Tree | Solution | |
| 110 | Balanced Binary Tree | Solution | |
| 111 | Minimum Depth of Binary Tree | Solution | |
| 112 | Path Sum | Solution | |
| 113 | Path Sum II | Solution | |
| 114 | Flatten Binary Tree to Linked List | Solution | |
| 115 | Distinct Subsequences | Hard | Solution |
| 116 | Populating Next Right Pointers in Each Node | Solution | |
| 117 | Populating Next Right Pointers in Each Node II | Solution | |
| 118 | Pascal's Triangle | Easy | Solution |
| 119 | Pascal's Triangle II | Easy | Solution |
| 121 | Best Time to Buy and Sell Stock | Easy | Solution |
| 122 | Best Time to Buy and Sell Stock II | Easy | Solution |
| 123 | Best Time to Buy and Sell Stock III | Hard | Solution |
| 124 | Binary Tree Maximum Path Sum | Hard | Solution |
| 125 | Valid Palindrome | Easy | Solution |
| 126 | Word Ladder II | Solution | |
| 127 | Word Ladder | Solution | |
| 128 | Longest Consecutive Sequence | Hard | Solution |
| 129 | Sum Root to Leaf Numbers | Medium | Solution |
| 130 | Surrounded Regions | Medium | Solution |
| 131 | Palindrome Partitioning | Solution | |
| 133 | Clone Graph | Medium | Solution |
| 134 | Gas Station | Medium | Solution |
| 136 | Single Number | Easy | Solution |
| 137 | Single Number II | Medium | Solution |
| 138 | Copy List with Random Pointer | Solution | |
| 139 | Word Break | Medium | Solution |
| 140 | Word Break II | Hard | Solution |
| 141 | Linked List Cycle | Solution | |
| 142 | Linked List Cycle II | Solution | |
| 143 | Reorder List | Medium | Solution |
| 144 | Binary Tree Preorder Traversal | Medium | Solution |
| 145 | Binary Tree Postorder Traversal | Hard | Solution |
| 146 | LRU Cache | Hard | Solution |
| 147 | Insertion Sort List | Solution | |
| 148 | Sort List | Solution | |
| 149 | Max Points on a Line | Hard | Solution |
| 150 | Evaluate Reverse Polish Notation | Solution | |
| 151 | Reverse Words in a String | Medium | Solution |
| 152 | Maximum Product Subarray | Medium | Solution |
| 153 | Find Minimum in Rotated Sorted Array | Medium | Solution |
| 154 | Find Minimum in Rotated Sorted Array II | Hard | Solution |
| 155 | Min Stack | Easy | Solution |
| 156 | Binary Tree Upside Down | Medium | Solution |
| 157 | Read N Characters Given Read4 | Easy | Solution |
| 158 | Read N Characters Given Read4 II - Call multiple times | Hard | Solution |
| 159 | Longest Substring with At Most Two Distinct Characters | Hard | Solution |
| 161 | One Edit Distance | Medium | Solution |
| 162 | Find Peak Element | Medium | Solution |
| 164 | Maximum Gap | Solution | |
| 166 | Fraction to Recurring Decimal | Solution | |
| 167 | Two Sum II - Input array is sorted | Solution | |
| 169 | Majority Element | Easy | Solution |
| 171 | Excel Sheet Column Number | Easy | Solution |
| 173 | Binary Search Tree Iterator | Medium | Solution |
| 174 | Dungeon Game | Hard | Solution |
| 175 | Combine Two Tables | Easy | Solution |
| 176 | Second Highest Salary | Easy | Solution |
| 181 | Employees Earning More Than Their Managers | Easy | Solution |
| 182 | Duplicate Emails | Easy | Solution |
| 188 | Best Time to Buy and Sell Stock IV | Hard | Solution |
| 190 | Reverse Bits | Easy | Solution |
| 195 | Tenth Line | Easy | Solution |
| 198 | House Robber | Easy | Solution |
| 200 | Number of Islands | Medium | Solution |
| 201 | Bitwise AND of Numbers Range | Medium | Solution |
| 202 | Happy Number | Easy | Solution |
| 203 | Remove Linked List Elements | Easy | Solution |
| 204 | Count Primes | Solution | |
| 206 | Reverse Linked List | Easy | Solution |
| 207 | Course Schedule | Medium | Solution |
| 208 | Implement Trie (Prefix Tree) | Medium | Solution |
| 209 | Minimum Size Subarray Sum | Medium | Solution |
| 210 | Course Schedule II | Medium | Solution |
| 211 | Add and Search Word - Data structure design | Medium | Solution |
| 212 | Word Search II | Hard | Solution |
| 213 | House Robber II | Medium | Solution |
| 214 | Shortest Palindrome | Solution | |
| 215 | Kth Largest Element in an Array | Medium | Solution |
| 216 | Combination Sum III | Medium | Solution |
| 218 | The Skyline Problem | Hard | Solution |
| 221 | Maximal Square | Medium | Solution |
| 222 | Count Complete Tree Nodes | Medium | Solution |
| 223 | Rectangle Area | Solution | |
| 224 | Basic Calculator | Hard | Solution |
| 225 | Implement Stack using Queues | Easy | Solution |
| 226 | Invert Binary Tree | Easy | Solution |
| 227 | Basic Calculator II | Medium | Solution |
| 229 | Majority Element II | Solution | |
| 230 | Kth Smallest Element in a BST | Medium | Solution |
| 231 | Power of Two | Easy | Solution |
| 232 | Implement Queue using Stacks | Easy | Solution |
| 234 | Palindrome Linked List | Easy | Solution |
| 237 | Delete Node in a Linked List | Easy | Solution |
| 238 | Product of Array Except Self | Medium | Solution |
| 239 | Sliding Window Maximum | Hard | Solution |
| 240 | Search a 2D Matrix II | Solution | |
| 241 | Different Ways to Add Parentheses | Medium | Solution |
| 243 | Shortest Word Distance | Easy | Solution |
| 244 | Shortest Word Distance II | Medium | Solution |
| 246 | Strobogrammatic Number | Easy | Solution |
| 247 | Strobogrammatic Number II | Medium | Solution |
| 249 | Group Shifted Strings | Medium | Solution |
| 250 | Count Univalue Subtrees | Medium | Solution |
| 252 | Meeting Rooms | Easy | Solution |
| 253 | Meeting Rooms II | Medium | Solution |
| 256 | Paint House | Easy | Solution |
| 257 | Binary Tree Paths | Easy | Solution |
| 258 | Add Digits | Easy | Solution |
| 259 | 3Sum Smaller | Medium | Solution |
| 260 | Single Number III | Medium | Solution |
| 261 | Graph Valid Tree | Medium | Solution |
| 263 | Ugly Number | Solution | |
| 264 | Ugly Number II | Medium | Solution |
| 266 | Palindrome Permutation | Easy | Solution |
| 268 | Missing Number | Easy | Solution |
| 270 | Closest Binary Search Tree Value | Easy | Solution |
| 271 | Encode and Decode Strings | Medium | Solution |
| 274 | H-Index | Medium | Solution |
| 275 | H-Index II | Medium | Solution |
| 278 | First Bad Version | Easy | Solution |
| 279 | Perfect Squares | Medium | Solution |
| 280 | Wiggle Sort | Medium | Solution |
| 281 | Zigzag Iterator | Medium | Solution |
| 285 | Inorder Successor in BST | Medium | Solution |
| 287 | Find the Duplicate Number | Medium | Solution |
| 289 | Game of Life | Medium | Solution |
| 293 | Flip Game | Easy | Solution |
| 295 | Find Median from Data Stream | Hard | Solution |
| 297 | Serialize and Deserialize Binary Tree | Hard | Solution |
| 298 | Binary Tree Longest Consecutive Sequence | Medium | Solution |
| 299 | Bulls and Cows | Solution | |
| 300 | Longest Increasing Subsequence | Medium | Solution |
| 301 | Remove Invalid Parentheses | Hard | Solution |
| 303 | Range Sum Query - Immutable | Solution | |
| 304 | Range Sum Query 2D - Immutable | Solution | |
| 307 | Range Sum Query - Mutable | Medium | Solution |
| 309 | Best Time to Buy and Sell Stock with Cooldown | Medium | Solution |
| 310 | Minimum Height Trees | Medium | Solution |
| 312 | Burst Balloons | Hard | Solution |
| 313 | Super Ugly Number | Solution | |
| 315 | Count of Smaller Numbers After Self | Solution | |
| 316 | Remove Duplicate Letters | Hard | Solution |
| 320 | Generalized Abbreviation | Medium | Solution |
| 321 | Create Maximum Number | Hard | Solution |
| 322 | Coin Change | Solution | |
| 324 | Wiggle Sort II | Solution | |
| 327 | Count of Range Sum | Solution | |
| 328 | Odd Even Linked List | Medium | Solution |
| 329 | Longest Increasing Path in a Matrix | Hard | Solution |
| 330 | Patching Array | Solution | |
| 331 | Verify Preorder Serialization of a Binary Tree | Solution | |
| 332 | Reconstruct Itinerary | Medium | Solution |
| 333 | Largest BST Subtree | Medium | Solution |
| 334 | Increasing Triplet Subsequence | Solution | |
| 335 | Self Crossing | Solution | |
| 336 | Palindrome Pairs | Hard | Solution |
| 337 | House Robber III | Medium | Solution |
| 338 | Counting Bits | Medium | Solution |
| 339 | Nested List Weight Sum | Easy | Solution |
| 340 | Longest Substring with At Most K Distinct Characters | Hard | Solution |
| 341 | Flatten Nested List Iterator | Medium | Solution |
| 342 | Power of Four | Easy | Solution |
| 343 | Integer Break | Medium | Solution |
| 344 | Reverse String | Easy | Solution |
| 345 | Reverse Vowels of a String | Easy | Solution |
| 346 | Moving Average from Data Stream | Easy | Solution |
| 347 | Top K Frequent Elements | Medium | Solution |
| 348 | Design Tic-Tac-Toe | Medium | Solution |
| 349 | Intersection of Two Arrays | Solution | |
| 350 | Intersection of Two Arrays II | Solution | |
| 352 | Data Stream as Disjoint Intervals | Solution | |
| 354 | Russian Doll Envelopes | Solution | |
| 355 | Design Twitter | Medium | Solution |
| 357 | Count Numbers with Unique Digits | Solution | |
| 359 | Logger Rate Limiter | Easy | Solution |
| 360 | Sort Transformed Array | Medium | Solution |
| 361 | Bomb Enemy | Medium | Solution |
| 363 | Max Sum of Rectangle No Larger Than K | Hard | Solution |
| 364 | Nested List Weight Sum II | Medium | Solution |
| 365 | Water and Jug Problem | Solution | |
| 366 | Find Leaves of Binary Tree | Medium | Solution |
| 367 | Valid Perfect Square | Easy | Solution |
| 368 | Largest Divisible Subset | Medium | Solution |
| 369 | Plus One Linked List | Medium | Solution |
| 370 | Range Addition | Medium | Solution |
| 371 | Sum of Two Integers | Easy | Solution |
| 372 | Super Pow | Solution | |
| 373 | Find K Pairs with Smallest Sums | Solution | |
| 374 | Guess Number Higher or Lower | Solution | |
| 375 | Guess Number Higher or Lower II | Medium | Solution |
| 376 | Wiggle Subsequence | Medium | Solution |
| 377 | Combination Sum IV | Medium | Solution |
| 378 | Kth Smallest Element in a Sorted Matrix | Solution | |
| 379 | Design Phone Directory | Medium | Solution |
| 380 | Insert Delete GetRandom O(1) | Medium | Solution |
| 381 | Insert Delete GetRandom O(1) - Duplicates allowed | Solution | |
| 382 | Linked List Random Node | Solution | |
| 383 | Ransom Note | Easy | Solution |
| 384 | Shuffle an Array | Solution | |
| 385 | Mini Parser | Medium | Solution |
| 386 | Lexicographical Numbers | Medium | Solution |
| 387 | First Unique Character in a String | Easy | Solution |
| 388 | Longest Absolute File Path | Medium | Solution |
| 389 | Find the Difference | Solution | |
| 390 | Elimination Game | Solution | |
| 391 | Perfect Rectangle | Solution | |
| 392 | Is Subsequence | Easy | Solution |
| 393 | UTF-8 Validation | Solution | |
| 394 | Decode String | Solution | |
| 395 | Longest Substring with At Least K Repeating Characters | Solution | |
| 396 | Rotate Function | Medium | Solution |
| 397 | Integer Replacement | Solution | |
| 398 | Random Pick Index | Solution | |
| 399 | Evaluate Division | Solution | |
| 400 | Nth Digit | Medium | Solution |
| 401 | Binary Watch | Solution | |
| 402 | Remove K Digits | Medium | Solution |
| 403 | Frog Jump | Solution | |
| 404 | Sum of Left Leaves | Solution | |
| 405 | Convert a Number to Hexadecimal | Solution | |
| 406 | Queue Reconstruction by Height | Medium | Solution |
| 407 | Trapping Rain Water II | Solution | |
| 408 | Valid Word Abbreviation | Easy | Solution |
| 409 | Longest Palindrome | Easy | Solution |
| 410 | Split Array Largest Sum | Hard | Solution |
| 412 | Fizz Buzz | Easy | Solution |
| 413 | Arithmetic Slices | Medium | Solution |
| 414 | Third Maximum Number | Solution | |
| 415 | Add Strings | Easy | Solution |
| 416 | Partition Equal Subset Sum | Medium | Solution |
| 417 | Pacific Atlantic Water Flow | Solution | |
| 419 | Battleships in a Board | Solution | |
| 420 | Strong Password Checker | Solution | |
| 421 | Maximum XOR of Two Numbers in an Array | Solution | |
| 422 | Valid Word Square | Easy | Solution |
| 423 | Reconstruct Original Digits from English | Solution | |
| 424 | Longest Repeating Character Replacement | Solution | |
| 427 | Construct Quad Tree | Easy | Solution |
| 429 | N-ary Tree Level Order Traversal | Easy | Solution |
| 430 | Flatten a Multilevel Doubly Linked List | Medium | Solution |
| 432 | All O`one Data Structure | Solution | |
| 434 | Number of Segments in a String | Solution | |
| 435 | Non-overlapping Intervals | Medium | Solution |
| 436 | Find Right Interval | Solution | |
| 437 | Path Sum III | Medium | Solution |
| 438 | Find All Anagrams in a String | Medium | Solution |
| 440 | K-th Smallest in Lexicographical Order | Solution | |
| 441 | Arranging Coins | Easy | Solution |
| 442 | Find All Duplicates in an Array | Medium | Solution |
| 443 | String Compression | Easy | Solution |
| 445 | Add Two Numbers II | Solution | |
| 446 | Arithmetic Slices II - Subsequence | Hard | Solution |
| 447 | Number of Boomerangs | Solution | |
| 448 | Find All Numbers Disappeared in an Array | Solution | |
| 449 | Serialize and Deserialize BST | Solution | |
| 450 | Delete Node in a BST | Medium | Solution |
| 451 | Sort Characters By Frequency | Medium | Solution |
| 452 | Minimum Number of Arrows to Burst Balloons | Solution | |
| 453 | Minimum Moves to Equal Array Elements | Solution | |
| 454 | 4Sum II | Medium | Solution |
| 455 | Assign Cookies | Solution | |
| 456 | 132 Pattern | Medium | Solution |
| 459 | Repeated Substring Pattern | Solution | |
| 460 | LFU Cache | Solution | |
| 461 | Hamming Distance | Easy | Solution |
| 462 | Minimum Moves to Equal Array Elements II | Solution | |
| 463 | Island Perimeter | Easy | Solution |
| 464 | Can I Win | Solution | |
| 466 | Count The Repetitions | Hard | Solution |
| 467 | Unique Substrings in Wraparound String | Solution | |
| 468 | Validate IP Address | Medium | Solution |
| 471 | Encode String with Shortest Length | Hard | Solution |
| 472 | Concatenated Words | Hard | Solution |
| 473 | Matchsticks to Square | Solution | |
| 474 | Ones and Zeroes | Medium | Solution |
| 475 | Heaters | Solution | |
| 476 | Number Complement | Easy | Solution |
| 477 | Total Hamming Distance | Solution | |
| 478 | Generate Random Point in a Circle | Medium | Solution |
| 480 | Sliding Window Median | Solution | |
| 481 | Magical String | Solution | |
| 482 | License Key Formatting | Solution | |
| 483 | Smallest Good Base | Hard | Solution |
| 485 | Max Consecutive Ones | Solution | |
| 486 | Predict the Winner | Medium | Solution |
| 487 | Max Consecutive Ones II | Solution | |
| 488 | Zuma Game | Solution | |
| 489 | Robot Room Cleaner | Hard | Solution |
| 490 | The Maze | Medium | Solution |
| 491 | Increasing Subsequences | Medium | Solution |
| 492 | Construct the Rectangle | Solution | |
| 494 | Target Sum | Medium | Solution |
| 495 | Teemo Attacking | Solution | |
| 496 | Next Greater Element I | Easy | Solution |
| 498 | Diagonal Traverse | Solution | |
| 500 | Keyboard Row | Solution | |
| 501 | Find Mode in Binary Search Tree | Solution | |
| 502 | IPO | Solution | |
| 503 | Next Greater Element II | Medium | Solution |
| 504 | Base 7 | Solution | |
| 506 | Relative Ranks | Solution | |
| 507 | Perfect Number | Easy | Solution |
| 508 | Most Frequent Subtree Sum | Solution | |
| 509 | Fibonacci Number | Easy | Solution |
| 513 | Find Bottom Left Tree Value | Solution | |
| 514 | Freedom Trail | Hard | Solution |
| 515 | Find Largest Value in Each Tree Row | Solution | |
| 516 | Longest Palindromic Subsequence | Medium | Solution |
| 517 | Super Washing Machines | Hard | Solution |
| 518 | Coin Change 2 | Medium | Solution |
| 519 | Random Flip Matrix | Medium | Solution |
| 520 | Detect Capital | Easy | Solution |
| 521 | Longest Uncommon Subsequence I | Easy | Solution |
| 523 | Continuous Subarray Sum | Medium | Solution |
| 524 | Longest Word in Dictionary through Deleting | Solution | |
| 525 | Contiguous Array | Medium | Solution |
| 526 | Beautiful Arrangement | Medium | Solution |
| 528 | Random Pick with Weight | Medium | Solution |
| 529 | Minesweeper | Solution | |
| 530 | Minimum Absolute Difference in BST | Solution | |
| 532 | K-diff Pairs in an Array | Easy | Solution |
| 535 | Encode and Decode TinyURL | Solution | |
| 536 | Construct Binary Tree from String | Solution | |
| 537 | Complex Number Multiplication | Medium | Solution |
| 538 | Convert BST to Greater Tree | Solution | |
| 539 | Minimum Time Difference | Solution | |
| 540 | Single Element in a Sorted Array | Medium | Solution |
| 541 | Reverse String II | Solution | |
| 542 | 01 Matrix | Solution | |
| 543 | Diameter of Binary Tree | Easy | Solution |
| 544 | Output Contest Matches | Medium | Solution |
| 546 | Remove Boxes | Hard | Solution |
| 547 | Friend Circles | Medium | Solution |
| 549 | Binary Tree Longest Consecutive Sequence II | Solution | |
| 551 | Student Attendance Record I | Easy | Solution |
| 552 | Student Attendance Record II | Hard | Solution |
| 553 | Optimal Division | Medium | Solution |
| 554 | Brick Wall | Medium | Solution |
| 556 | Next Greater Element III | Medium | Solution |
| 557 | Reverse Words in a String III | Solution | |
| 558 | Quad Tree Intersection | Easy | Solution |
| 559 | Maximum Depth of N-ary Tree | Easy | Solution |
| 560 | Subarray Sum Equals K | Medium | Solution |
| 561 | Array Partition I | Solution | |
| 562 | Longest Line of Consecutive One in Matrix | Solution | |
| 563 | Binary Tree Tilt | Solution | |
| 566 | Reshape the Matrix | Easy | Solution |
| 567 | Permutation in String | Medium | Solution |
| 570 | Managers with at Least 5 Direct Reports | Medium | Solution |
| 572 | Subtree of Another Tree | Easy | Solution |
| 575 | Distribute Candies | Easy | Solution |
| 576 | Out of Boundary Paths | Medium | Solution |
| 577 | Employee Bonus | Easy | Solution |
| 581 | Shortest Unsorted Continuous Subarray | Easy | Solution |
| 582 | Kill Process | Medium | Solution |
| 583 | Delete Operation for Two Strings | Medium | Solution |
| 584 | Find Customer Referee | Easy | Solution |
| 586 | Customer Placing the Largest Number of Orders | Easy | Solution |
| 589 | N-ary Tree Preorder Traversal | Easy | Solution |
| 590 | N-ary Tree Postorder Traversal | Easy | Solution |
| 591 | Tag Validator | Hard | Solution |
| 593 | Valid Square | Medium | Solution |
| 594 | Longest Harmonious Subsequence | Easy | Solution |
| 595 | Big Countries | Easy | Solution |
| 597 | Friend Requests I: Overall Acceptance Rate | Easy | Solution |
| 599 | Minimum Index Sum of Two Lists | Easy | Solution |
| 600 | Non-negative Integers without Consecutive Ones | Hard | Solution |
| 603 | Consecutive Available Seats | Easy | Solution |
| 604 | Design Compressed String Iterator | Easy | Solution |
| 605 | Can Place Flowers | Easy | Solution |
| 606 | Construct String from Binary Tree | Easy | Solution |
| 607 | Sales Person | Easy | Solution |
| 609 | Find Duplicate File in System | Medium | Solution |
| 610 | Triangle Judgement | Easy | Solution |
| 611 | Valid Triangle Number | Medium | Solution |
| 613 | Shortest Distance in a Line | Easy | Solution |
| 616 | Add Bold Tag in String | Medium | Solution |
| 617 | Merge Two Binary Trees | Easy | Solution |
| 620 | Not Boring Movies | Easy | Solution |
| 621 | Task Scheduler | Medium | Solution |
| 622 | Design Circular Queue | Medium | Solution |
| 627 | Swap Salary | Easy | Solution |
| 628 | Maximum Product of Three Numbers | Easy | Solution |
| 629 | K Inverse Pairs Array | Hard | Solution |
| 636 | Exclusive Time of Functions | Medium | Solution |
| 637 | Average of Levels in Binary Tree | Easy | Solution |
| 638 | Shopping Offers | Medium | Solution |
| 639 | Decode Ways II | Hard | Solution |
| 640 | Solve the Equation | Medium | Solution |
| 643 | Maximum Average Subarray I | Easy | Solution |
| 645 | Set Mismatch | Easy | Solution |
| 647 | Palindromic Substrings | Medium | Solution |
| 648 | Replace Words | Medium | Solution |
| 650 | 2 Keys Keyboard | Medium | Solution |
| 651 | 4 Keys Keyboard | Medium | Solution |
| 652 | Find Duplicate Subtrees | Medium | Solution |
| 653 | Two Sum IV - Input is a BST | Easy | Solution |
| 654 | Maximum Binary Tree | Medium | Solution |
| 655 | Print Binary Tree | Medium | Solution |
| 657 | Robot Return to Origin | Easy | Solution |
| 659 | Split Array into Consecutive Subsequences | Medium | Solution |
| 662 | Maximum Width of Binary Tree | Medium | Solution |
| 663 | Equal Tree Partition | Medium | Solution |
| 664 | Strange Printer | Hard | Solution |
| 666 | Path Sum IV | Medium | Solution |
| 668 | Kth Smallest Number in Multiplication Table | Hard | Solution |
| 669 | Trim a Binary Search Tree | Easy | Solution |
| 670 | Maximum Swap | Medium | Solution |
| 673 | Number of Longest Increasing Subsequence | Medium | Solution |
| 674 | Longest Continuous Increasing Subsequence | Easy | Solution |
| 676 | Implement Magic Dictionary | Medium | Solution |
| 677 | Map Sum Pairs | Medium | Solution |
| 678 | Valid Parenthesis String | Medium | Solution |
| 680 | Valid Palindrome II | Easy | Solution |
| 682 | Baseball Game | Easy | Solution |
| 684 | Redundant Connection | Medium | Solution |
| 687 | Longest Univalue Path | Easy | Solution |
| 688 | Knight Probability in Chessboard | Medium | Solution |
| 690 | Employee Importance | Easy | Solution |
| 691 | Stickers to Spell Word | Hard | Solution |
| 693 | Binary Number with Alternating Bits | Easy | Solution |
| 694 | Number of Distinct Islands | Medium | Solution |
| 695 | Max Area of Island | Medium | Solution |
| 697 | Degree of an Array | Easy | Solution |
| 699 | Falling Squares | Hard | Solution |
| 700 | Search in a Binary Search Tree | Easy | Solution |
| 701 | Insert into a Binary Search Tree | Medium | Solution |
| 702 | Search in a Sorted Array of Unknown Size | Medium | Solution |
| 703 | Kth Largest Element in a Stream | Easy | Solution |
| 704 | Binary Search | Easy | Solution |
| 705 | Design HashSet | Easy | Solution |
| 706 | Design HashMap | Easy | Solution |
| 707 | Design Linked List | Easy | Solution |
| 709 | To Lower Case | Easy | Solution |
| 712 | Minimum ASCII Delete Sum for Two Strings | Medium | Solution |
| 714 | Best Time to Buy and Sell Stock with Transaction Fee | Medium | Solution |
| 717 | 1-bit and 2-bit Characters | Easy | Solution |
| 718 | Maximum Length of Repeated Subarray | Medium | Solution |
| 719 | Find K-th Smallest Pair Distance | Hard | Solution |
| 720 | Longest Word in Dictionary | Easy | Solution |
| 721 | Accounts Merge | Medium | Solution |
| 723 | Candy Crush | Medium | Solution |
| 724 | Find Pivot Index | Easy | Solution |
| 725 | Split Linked List in Parts | Medium | Solution |
| 726 | Number of Atoms | Hard | Solution |
| 728 | Self Dividing Numbers | Easy | Solution |
| 730 | Count Different Palindromic Subsequences | Hard | Solution |
| 733 | Flood Fill | Easy | Solution |
| 735 | Asteroid Collision | Medium | Solution |
| 739 | Daily Temperatures | Medium | Solution |
| 740 | Delete and Earn | Medium | Solution |
| 743 | Network Delay Time | Medium | Solution |
| 744 | Find Smallest Letter Greater Than Target | Easy | Solution |
| 745 | Prefix and Suffix Search | Hard | Solution |
| 746 | Min Cost Climbing Stairs | Easy | Solution |
| 747 | Largest Number At Least Twice of Others | Easy | Solution |
| 748 | Shortest Completing Word | Easy | Solution |
| 750 | Number Of Corner Rectangles | Medium | Solution |
| 751 | IP to CIDR | Hard | Solution |
| 752 | Open the Lock | Medium | Solution |
| 753 | Cracking the Safe | Hard | Solution |
| 754 | Reach a Number | Easy | Solution |
| 755 | Pour Water | Medium | Solution |
| 760 | Find Anagram Mappings | Easy | Solution |
| 762 | Prime Number of Set Bits in Binary Representation | Easy | Solution |
| 763 | Partition Labels | Medium | Solution |
| 765 | Couples Holding Hands | Hard | Solution |
| 766 | Toeplitz Matrix | Easy | Solution |
| 767 | Reorganize String | Medium | Solution |
| 768 | Max Chunks To Make Sorted II | Hard | Solution |
| 769 | Max Chunks To Make Sorted | Medium | Solution |
| 770 | Basic Calculator IV | Hard | Solution |
| 771 | Jewels and Stones | Easy | Solution |
| 775 | Global and Local Inversions | Medium | Solution |
| 777 | Swap Adjacent in LR String | Medium | Solution |
| 783 | Minimum Distance Between BST Nodes | Medium | Solution |
| 784 | Letter Case Permutation | Easy | Solution |
| 785 | Is Graph Bipartite? | Medium | Solution |
| 787 | Cheapest Flights Within K Stops | Medium | Solution |
| 788 | Rotated Digits | Easy | Solution |
| 791 | Custom Sort String | Medium | Solution |
| 793 | Preimage Size of Factorial Zeroes Function | Hard | Solution |
| 794 | Valid Tic-Tac-Toe State | Medium | Solution |
| 795 | Number of Subarrays with Bounded Maximum | Medium | Solution |
| 796 | Rotate String | Easy | Solution |
| 797 | All Paths From Source to Target | Medium | Solution |
| 798 | Smallest Rotation with Highest Score | Solution | |
| 800 | Similar RGB Color | Easy | Solution |
| 801 | Minimum Swaps To Make Sequences Increasing | Medium | Solution |
| 802 | Find Eventual Safe States | Medium | Solution |
| 804 | Unique Morse Code Words | Easy | Solution |
| 805 | Split Array With Same Average | Hard | Solution |
| 806 | Number of Lines To Write String | Easy | Solution |
| 807 | Max Increase to Keep City Skyline | Medium | Solution |
| 809 | Expressive Words | Medium | Solution |
| 811 | Subdomain Visit Count | Easy | Solution |
| 812 | Largest Triangle Area | Easy | Solution |
| 813 | Largest Sum of Averages | Medium | Solution |
| 814 | Binary Tree Pruning | Medium | Solution |
| 817 | Linked List Components | Medium | Solution |
| 819 | Most Common Word | Easy | Solution |
| 821 | Shortest Distance to a Character | Easy | Solution |
| 823 | Binary Trees With Factors | Medium | Solution |
| 824 | Goat Latin | Easy | Solution |
| 825 | Friends Of Appropriate Ages | Medium | Solution |
| 826 | Most Profit Assigning Work | Medium | Solution |
| 827 | Making A Large Island | Hard | Solution |
| 828 | Unique Letter String | Hard | Solution |
| 829 | Consecutive Numbers Sum | Hard | Solution |
| 830 | Positions of Large Groups | Easy | Solution |
| 832 | Flipping an Image | Easy | Solution |
| 835 | Image Overlap | Medium | Solution |
| 836 | Rectangle Overlap | Easy | Solution |
| 837 | New 21 Game | Medium | Solution |
| 840 | Magic Squares In Grid | Easy | Solution |
| 841 | Keys and Rooms | Medium | Solution |
| 843 | Guess the Word | Hard | Solution |
| 844 | Backspace String Compare | Easy | Solution |
| 846 | Hand of Straights | Medium | Solution |
| 852 | Peak Index in a Mountain Array | Easy | Solution |
| 856 | Score of Parentheses | Medium | Solution |
| 857 | Minimum Cost to Hire K Workers | Hard | Solution |
| 859 | Buddy Strings | Easy | Solution |
| 860 | Lemonade Change | Easy | Solution |
| 861 | Score After Flipping Matrix | Medium | Solution |
| 862 | Shortest Subarray with Sum at Least K | Hard | Solution |
| 863 | All Nodes Distance K in Binary Tree | Medium | Solution |
| 867 | Transpose Matrix | Easy | Solution |
| 868 | Binary Gap | Easy | Solution |
| 869 | Reordered Power of 2 | Medium | Solution |
| 870 | Advantage Shuffle | Medium | Solution |
| 872 | Leaf-Similar Trees | Easy | Solution |
| 874 | Walking Robot Simulation | Easy | Solution |
| 875 | Koko Eating Bananas | Medium | Solution |
| 876 | Middle of the Linked List | Easy | Solution |
| 877 | Stone Game | Medium | Solution |
| 881 | Boats to Save People | Medium | Solution |
| 883 | Projection Area of 3D Shapes | Easy | Solution |
| 884 | Uncommon Words from Two Sentences | Easy | Solution |
| 885 | Spiral Matrix III | Medium | Solution |
| 886 | Possible Bipartition | Medium | Solution |
| 887 | Super Egg Drop | Hard | Solution |
| 888 | Fair Candy Swap | Easy | Solution |
| 889 | Construct Binary Tree from Preorder and Postorder Traversal | Medium | Solution |
| 890 | Find and Replace Pattern | Medium | Solution |
| 891 | Sum of Subsequence Widths | Solution | |
| 892 | Surface Area of 3D Shapes | Easy | Solution |
| 893 | Groups of Special-Equivalent Strings | Easy | Solution |
| 894 | All Possible Full Binary Trees | Medium | Solution |
| 896 | Monotonic Array | Easy | Solution |
| 897 | Increasing Order Search Tree | Easy | Solution |
| 899 | Orderly Queue | Hard | Solution |
| 901 | Online Stock Span | Medium | Solution |
| 902 | Numbers At Most N Given Digit Set | Hard | Solution |
| 903 | Valid Permutations for DI Sequence | Hard | Solution |
| 905 | Sort Array By Parity | Easy | Solution |
| 906 | Super Palindromes | Hard | Solution |
| 908 | Smallest Range I | Easy | Solution |
| 911 | Online Election | Medium | Solution |
| 912 | Sort an Array | Medium | Solution |
| 914 | X of a Kind in a Deck of Cards | Easy | Solution |
| 917 | Reverse Only Letters | Easy | Solution |
| 918 | Maximum Sum Circular Subarray | Medium | Solution |
| 919 | Complete Binary Tree Inserter | Medium | Solution |
| 921 | Minimum Add to Make Parentheses Valid | Medium | Solution |
| 922 | Sort Array By Parity II | Easy | Solution |
| 923 | 3Sum With Multiplicity | Medium | Solution |
| 924 | Minimize Malware Spread | Hard | Solution |
| 926 | Flip String to Monotone Increasing | Medium | Solution |
| 928 | Minimize Malware Spread II | Hard | Solution |
| 929 | Unique Email Addresses | Easy | Solution |
| 930 | Binary Subarrays With Sum | Medium | Solution |
| 931 | Minimum Falling Path Sum | Medium | Solution |
| 932 | Beautiful Array | Medium | Solution |
| 933 | Number of Recent Calls | Easy | Solution |
| 935 | Knight Dialer | Medium | Solution |
| 936 | Stamping The Sequence | Hard | Solution |
| 937 | Reorder Log Files | Easy | Solution |
| 938 | Range Sum of BST | Easy | Solution |
| 939 | Minimum Area Rectangle | Medium | Solution |
| 940 | Distinct Subsequences II | Hard | Solution |
| 941 | Valid Mountain Array | Easy | Solution |
| 942 | DI String Match | Easy | Solution |
| 943 | Find the Shortest Superstring | Hard | Solution |
| 944 | Delete Columns to Make Sorted | Easy | Solution |
| 945 | Minimum Increment to Make Array Unique | Medium | Solution |
| 946 | Validate Stack Sequences | Medium | Solution |
| 947 | Most Stones Removed with Same Row or Column | Medium | Solution |
| 948 | Bag of Tokens | Medium | Solution |
| 949 | Largest Time for Given Digits | Easy | Solution |
| 950 | Reveal Cards In Increasing Order | Medium | Solution |
| 951 | Flip Equivalent Binary Trees | Medium | Solution |
| 952 | Largest Component Size by Common Factor | Hard | Solution |
| 953 | Verifying an Alien Dictionary | Easy | Solution |
| 954 | Array of Doubled Pairs | Medium | Solution |
| 955 | Delete Columns to Make Sorted II | Medium | Solution |
| 956 | Tallest Billboard | Hard | Solution |
| 957 | Prison Cells After N Days | Medium | Solution |
| 958 | Check Completeness of a Binary Tree | Medium | Solution |
| 959 | Regions Cut By Slashes | Medium | Solution |
| 961 | N-Repeated Element in Size 2N Array | Easy | Solution |
| 962 | Maximum Width Ramp | Medium | Solution |
| 968 | Binary Tree Cameras | Hard | Solution |
| 969 | Pancake Sorting | Medium | Solution |
| 970 | Powerful Integers | Easy | Solution |
| 971 | Flip Binary Tree To Match Preorder Traversal | Medium | Solution |
| 973 | K Closest Points to Origin | Easy | Solution |
| 977 | Squares of a Sorted Array | Easy | Solution |
| 978 | Longest Turbulent Subarray | Medium | Solution |
| 979 | Distribute Coins in Binary Tree | Medium | Solution |
| 980 | Unique Paths III | Hard | Solution |
| 983 | Minimum Cost For Tickets | Medium | Solution |
| 984 | String Without AAA or BBB | Medium | Solution |
| 985 | Sum of Even Numbers After Queries | Easy | Solution |
| 986 | Interval List Intersections | Medium | Solution |
| 987 | Vertical Order Traversal of a Binary Tree | Medium | Solution |
| 990 | Satisfiability of Equality Equations | Medium | Solution |
| 993 | Cousins in Binary Tree | Easy | Solution |
| 994 | Rotting Oranges | Medium | Solution |
| 997 | Find the Town Judge | Easy | Solution |
| 998 | Maximum Binary Tree II | Medium | Solution |
| 999 | Available Captures for Rook | Easy | Solution |
| 1000 | Minimum Cost to Merge Stones | Hard | Solution |
| 1002 | Find Common Characters | Easy | Solution |
| 1004 | Max Consecutive Ones III | Medium | Solution |
| 1008 | Construct Binary Search Tree from Preorder Traversal | Medium | Solution |
| 1011 | Capacity To Ship Packages Within D Days | Medium | Solution |
| 1012 | Complement of Base 10 Integer | Easy | Solution |
| 1013 | Pairs of Songs With Total Durations Divisible by 60 | Easy | Solution |
| 1014 | Best Sightseeing Pair | Medium | Solution |
| 1016 | Binary String With Substrings Representing 1 To N | Medium | Solution |
| 1019 | Next Greater Node In Linked List | Medium | Solution |
| 1020 | Number of Enclaves | Medium | Solution |
| 1021 | Remove Outermost Parentheses | Easy | Solution |
| 1022 | Sum of Root To Leaf Binary Numbers | Easy | Solution |
| 1025 | Divisor Game | Easy | Solution |
| 1027 | Longest Arithmetic Sequence | Medium | Solution |
| 1028 | Recover a Tree From Preorder Traversal | Hard | Solution |
| 1029 | Two City Scheduling | Easy | Solution |
| 1030 | Matrix Cells in Distance Order | Easy | Solution |
| 1031 | Maximum Sum of Two Non-Overlapping Subarrays | Medium | Solution |
| 1034 | Coloring A Border | Medium | Solution |
| 1035 | Uncrossed Lines | Medium | Solution |
| 1037 | Valid Boomerang | Easy | Solution |
| 1038 | Binary Search Tree to Greater Sum Tree | Medium | Solution |
| 1039 | Minimum Score Triangulation of Polygon | Medium | Solution |
| 1042 | Flower Planting With No Adjacent | Easy | Solution |
| 1043 | Partition Array for Maximum Sum | Medium | Solution |
| 1044 | Longest Duplicate Substring | Hard | Solution |
| 1046 | Last Stone Weight | Easy | Solution |
| 1047 | Remove All Adjacent Duplicates In String | Easy | Solution |
| 1053 | Previous Permutation With One Swap | Medium | Solution |
| 1054 | Distant Barcodes | Medium | Solution |
| 1071 | Greatest Common Divisor of Strings | Easy | Solution |
| 1072 | Flip Columns For Maximum Number of Equal Rows | Medium | Solution |
| 1073 | Adding Two Negabinary Numbers | Medium | Solution |
| 1074 | Number of Submatrices That Sum to Target | Hard | Solution |
| 1078 | Occurrences After Bigram | Easy | Solution |
| 1079 | Letter Tile Possibilities | Medium | Solution |
| 1080 | Insufficient Nodes in Root to Leaf Paths | Medium | Solution |
| 1081 | Smallest Subsequence of Distinct Characters | Medium | Solution |
| 1092 | Shortest Common Supersequence | Hard | Solution |
| 1096 | Brace Expansion II | Hard | Solution |
| 1104 | Path In Zigzag Labelled Binary Tree | Medium | Solution |
| 1105 | Filling Bookcase Shelves | Medium | Solution |
| 1106 | Parsing A Boolean Expression | Hard | Solution |
| 1108 | Defanging an IP Address | Easy | Solution |
| 1111 | Maximum Nesting Depth of Two Valid Parentheses Strings | Medium | Solution |
| 1125 | Smallest Sufficient Team | Hard | Solution |
| 1130 | Minimum Cost Tree From Leaf Values | Medium | Solution |
| 1140 | Stone Game II | Medium | Solution |
| 1143 | Longest Common Subsequence | Medium | Solution |
| 1146 | Snapshot Array | Medium | Solution |
| 1154 | Day of the Year | Easy | Solution |
| 1160 | Find Words That Can Be Formed by Characters | Easy | Solution |
| 1161 | Maximum Level Sum of a Binary Tree | Medium | Solution |
| 1162 | As Far from Land as Possible | Medium | Solution |
| 1163 | Last Substring in Lexicographical Order | Hard | Solution |
| 1169 | Invalid Transactions | Medium | Solution |
| 1184 | Distance Between Bus Stops | Easy | Solution |
| 1185 | Day of the Week | Easy | Solution |
| 1186 | Maximum Subarray Sum with One Deletion | Medium | Solution |
| 1187 | Make Array Strictly Increasing | Hard | Solution |
| 1189 | Maximum Number of Balloons | Easy | Solution |
| 1190 | Reverse Substrings Between Each Pair of Parentheses | Medium | Solution |
| 1203 | Sort Items by Groups Respecting Dependencies | Hard | Solution |
| 1207 | Unique Number of Occurrences | Easy | Solution |
| 1209 | Remove All Adjacent Duplicates in String II | Medium | Solution |
| 1220 | Count Vowels Permutation | Hard | Solution |
| 1223 | Dice Roll Simulation | Medium | Solution |
| 1232 | Check If It Is a Straight Line | Easy | Solution |
| 1235 | Maximum Profit in Job Scheduling | Hard | Solution |
| 1252 | Cells with Odd Values in a Matrix | Easy | Solution |
| 1266 | Minimum Time Visiting All Points | Easy | Solution |
| 1267 | Count Servers that Communicate | Medium | Solution |
| 1268 | Search Suggestions System | Medium | Solution |
| 1269 | Number of Ways to Stay in the Same Place After Some Steps | Hard | Solution |
| 1277 | Count Square Submatrices with All Ones | Medium | Solution |
| 1278 | Palindrome Partitioning III | Hard | Solution |
| 1282 | Group the People Given the Group Size They Belong To | Medium | Solution |
| 1286 | Iterator for Combination | Medium | Solution |
| 1288 | Remove Covered Intervals | Medium | Solution |
| 1289 | Minimum Falling Path Sum II | Hard | Solution |
| 1290 | Convert Binary Number in a Linked List to Integer | Easy | Solution |
| 1293 | Shortest Path in a Grid with Obstacles Elimination | Hard | Solution |
| 1295 | Find Numbers with Even Number of Digits | Easy | Solution |
| 1300 | Sum of Mutated Array Closest to Target | Medium | Solution |
| 1301 | Number of Paths with Max Score | Hard | Solution |
| 1312 | Minimum Insertion Steps to Make a String Palindrome | Hard | Solution |
| 1313 | Decompress Run-Length Encoded List | Easy | Solution |
| 1315 | Sum of Nodes with Even-Valued Grandparent | Medium | Solution |
| 1316 | Distinct Echo Substrings | Hard | Solution |
| 1319 | Number of Operations to Make Network Connected | Medium | Solution |
| 1320 | Minimum Distance to Type a Word Using Two Fingers | Hard | Solution |
| 1323 | Maximum 69 Number | Easy | Solution |
| 1324 | Print Words Vertically | Medium | Solution |
| 1325 | Delete Leaves With a Given Value | Medium | Solution |
| 1326 | Minimum Number of Taps to Open to Water a Garden | Hard | Solution |
| 1328 | Break a Palindrome | Medium | Solution |
| 1329 | Sort the Matrix Diagonally | Medium | Solution |
| 1330 | Reverse Subarray To Maximize Array Value | Hard | Solution |
| 1331 | Rank Transform of an Array | Easy | Solution |
| 1332 | Remove Palindromic Subsequences | Easy | Solution |
| 1333 | Filter Restaurants by Vegan-Friendly, Price and Distance | Medium | Solution |
| 1334 | Find the City With the Smallest Number of Neighbors at a Threshold Distance | Medium | Solution |
| 1335 | Minimum Difficulty of a Job Schedule | Hard | Solution |
| 1338 | Reduce Array Size to The Half | Medium | Solution |
| 1339 | Maximum Product of Splitted Binary Tree | Medium | Solution |
| 1340 | Jump Game V | Hard | Solution |
| 1341 | The K Weakest Rows in a Matrix | Easy | Solution |
| 1342 | Number of Steps to Reduce a Number to Zero | Easy | Solution |
| 1343 | Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold | Medium | Solution |
| 1344 | Angle Between Hands of a Clock | Medium | Solution |
| 1345 | Jump Game IV | Hard | Solution |
| 1346 | Check If N and Its Double Exist | Easy | Solution |
| 1347 | Minimum Number of Steps to Make Two Strings Anagram | Medium | Solution |
| 1348 | Tweet Counts Per Frequency | Medium | Solution |
| 1349 | Maximum Students Taking Exam | Hard | Solution |
| 1351 | Count Negative Numbers in a Sorted Matrix | Easy | Solution |
| 1352 | Product of the Last K Numbers | Medium | Solution |
| 1353 | Maximum Number of Events That Can Be Attended | Medium | Solution |
| 1354 | Construct Target Array With Multiple Sums | Hard | Solution |
| 1356 | Sort Integers by The Number of 1 Bits | Easy | Solution |
| 1357 | Apply Discount Every n Orders | Medium | Solution |
| 1358 | Number of Substrings Containing All Three Characters | Medium | Solution |
| 1359 | Count All Valid Pickup and Delivery Options | Hard | Solution |
| 1360 | Number of Days Between Two Dates | Easy | Solution |
| 1361 | Validate Binary Tree Nodes | Medium | Solution |
| 1367 | Linked List in Binary Tree | Medium | Solution |
| 1370 | Increasing Decreasing String | Easy | Solution |
| 1371 | Find the Longest Substring Containing Vowels in Even Counts | Medium | Solution |
| 1372 | Longest ZigZag Path in a Binary Tree | Medium | Solution |
| 1373 | Maximum Sum BST in Binary Tree | Hard | Solution |
| 1374 | Generate a String With Characters That Have Odd Counts | Easy | Solution |
| 1375 | Bulb Switcher III | Medium | Solution |
| 1376 | Time Needed to Inform All Employees | Medium | Solution |
| 1377 | Frog Position After T Seconds | Hard | Solution |
| 1380 | Lucky Numbers in a Matrix | Easy | Solution |
| 1381 | Design a Stack With Increment Operation | Medium | Solution |
| 1382 | Balance a Binary Search Tree | Medium | Solution |
| 1383 | Maximum Performance of a Team | Hard | Solution |
| 1385 | Find the Distance Value Between Two Arrays | Easy | Solution |
| 1386 | Cinema Seat Allocation | Medium | Solution |
| 1387 | Sort Integers by The Power Value | Medium | Solution |
| 1388 | Pizza With 3n Slices | Hard | Solution |
| 1389 | Create Target Array in the Given Order | Easy | Solution |
| 1390 | Four Divisors | Medium | Solution |
| 1391 | Check if There is a Valid Path in a Grid | Medium | Solution |
| 1392 | Longest Happy Prefix | Hard | Solution |
| 1397 | Find All Good Strings | Hard | Solution |
| 1399 | Count Largest Group | Easy | Solution |
| 1400 | Construct K Palindrome Strings | Medium | Solution |
| 1401 | Circle and Rectangle Overlapping | Medium | Solution |
| 1402 | Reducing Dishes | Hard | Solution |
| 1403 | Minimum Subsequence in Non-Increasing Order | Easy | Solution |
| 1404 | Number of Steps to Reduce a Number in Binary Representation to One | Medium | Solution |
| 1405 | Longest Happy String | Medium | Solution |
| 1406 | Stone Game III | Hard | Solution |
| 1408 | String Matching in an Array | Easy | Solution |
| 1409 | Queries on a Permutation With Key | Medium | Solution |
| 1410 | HTML Entity Parser | Medium | Solution |
| 1411 | Number of Ways to Paint N × 3 Grid | Hard | Solution |
| 1413 | Minimum Value to Get Positive Step by Step Sum | Easy | Solution |
| 1414 | Find the Minimum Number of Fibonacci Numbers Whose Sum Is K | Medium | Solution |
| 1415 | The k-th Lexicographical String of All Happy Strings of Length n | Medium | Solution |
| 1416 | Restore The Array | Hard | Solution |
| 1419 | Minimum Number of Frogs Croaking | Medium | Solution |
| 1420 | Build Array Where You Can Find The Maximum Exactly K Comparisons | Hard | Solution |
| 1422 | Maximum Score After Splitting a String | Easy | Solution |
| 1423 | Maximum Points You Can Obtain from Cards | Medium | Solution |
| 1424 | Diagonal Traverse II | Medium | Solution |
| 1425 | Constrained Subsequence Sum | Hard | Solution |
| 1428 | Leftmost Column with at Least a One | Medium | Solution |
| 1429 | First Unique Number | Medium | Solution |
| 1430 | Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree | Medium | Solution |
| 1434 | Number of Ways to Wear Different Hats to Each Other | Hard | Solution |
| 1436 | Destination City | Easy | Solution |
| 1437 | Check If All 1's Are at Least Length K Places Away | Medium | Solution |
| 1438 | Longest Continuous Subarray With Absolute Diff Less Than or Equal to Limit | Medium | Solution |
| 1439 | Find the Kth Smallest Sum of a Matrix With Sorted Rows | Hard | Solution |
| 1441 | Build an Array With Stack Operations | Solution | |
| 1443 | Minimum Time to Collect All Apples in a Tree | Medium | Solution |
| 1444 | Number of Ways of Cutting a Pizza | Hard | Solution |
| 1446 | Consecutive Characters | Easy | Solution |
| 1447 | Simplified Fractions | Medium | Solution |
| 1448 | Count Good Nodes in Binary Tree | Medium | Solution |
| 1449 | Form Largest Integer With Digits That Add up to Target | Hard | Solution |
| 1455 | Check If a Word Occurs As a Prefix of Any Word in a Sentence | Easy | Solution |
| 1456 | Maximum Number of Vowels in a Substring of Given Length | Medium | Solution |
| 1457 | Pseudo-Palindromic Paths in a Binary Tree | Medium | Solution |
| 1458 | Max Dot Product of Two Subsequences | Hard | Solution |
| 1460 | Make Two Arrays Equal by Reversing Sub-arrays | Easy | Solution |
| 1461 | Check If a String Contains All Binary Codes of Size K | Medium | Solution |
| 1462 | Course Schedule IV | Medium | Solution |
| 1463 | Cherry Pickup II | Hard | Solution |
| 1464 | Maximum Product of Two Elements in an Array | Easy | Solution |
| 1467 | Probability of a Two Boxes Having The Same Number of Distinct Balls | Hard | Solution |
| 1470 | Shuffle the Array | Easy | Solution |
| 1471 | The k Strongest Values in an Array | Medium | Solution |
| 1472 | Design Browser History | Medium | Solution |
| 1473 | Paint House III | Hard | Solution |
| 1475 | Final Prices With a Special Discount in a Shop | Easy | Solution |
| 1476 | Subrectangle Queries | Medium | Solution |
| 1477 | Find Two Non-overlapping Sub-arrays Each With Target Sum | Solution | |
| 1478 | Allocate Mailboxes | Hard | Solution |
| 1480 | Running Sum of 1d Array | Easy | Solution |
| 1481 | Least Number of Unique Integers after K Removals | Medium | Solution |
| 1482 | Minimum Number of Days to Make m Bouquets | Medium | Solution |
| 1483 | Kth Ancestor of a Tree Node | Hard | Solution |
| 1486 | XOR Operation in an Array | Easy | Solution |
| 1487 | Making File Names Unique | Medium | Solution |
| 1488 | Avoid Flood in The City | Medium | Solution |
| 1491 | Average Salary Excluding the Minimum and Maximum Salary | Easy | Solution |
| 1492 | The kth Factor of n | Medium | Solution |
| 1493 | Longest Subarray of 1's After Deleting One Element | Medium | Solution |
| 1494 | Parallel Courses II | Hard | Solution |
| 1496 | Path Crossing | Easy | Solution |
| 1497 | Check If Array Pairs Are Divisible by k | Medium | Solution |
| 1498 | Number of Subsequences That Satisfy the Given Sum Condition | Medium | Solution |
| 1499 | Max Value of Equation | Hard | Solution |
| 1502 | Can Make Arithmetic Progression From Sequence | Easy | Solution |
| 1503 | Last Moment Before All Ants Fall Out of a Plank | Medium | Solution |
| 1504 | Count Submatrices With All Ones | Medium | Solution |
| 1505 | Minimum Possible Integer After at Most K Adjacent Swaps On Digits | Hard | Solution |
| 1507 | Reformat Date | Easy | Solution |
| 1508 | Range Sum of Sorted Subarray Sums | Medium | Solution |
| 1509 | Minimum Difference Between Largest and Smallest Value in Three Moves | Medium | Solution |
| 1510 | Stone Game IV | Hard | Solution |
| 1512 | Number of Good Pairs | Easy | Solution |
| 1513 | Number of Substrings With Only 1s | Medium | Solution |
| 1514 | Path with Maximum Probability | Medium | Solution |
| 1515 | Best Position for a Service Centre | Hard | Solution |
| 1518 | Water Bottles | Easy | Solution |
| 1519 | Number of Nodes in the Sub-Tree With the Same Label | Medium | Solution |
| 1520 | Maximum Number of Non-Overlapping Substrings | Medium | Solution |
| 1521 | Find a Value of a Mysterious Function Closest to Target | Hard | Solution |
| 1523 | Count Odd Numbers in an Interval Range | Easy | Solution |
| 1524 | Number of Sub-arrays With Odd Sum | Medium | Solution |
| 1525 | Number of Good Ways to Split a String | Medium | Solution |
| 1526 | Minimum Number of Increments on Subarrays to Form a Target Array | Hard | Solution |
| 1531 | String Compression II | Hard | Solution |
| 1534 | Count Good Triplets | Easy | Solution |
| 1535 | Find the Winner of an Array Game | Medium | Solution |
| 1536 | Minimum Swaps to Arrange a Binary Grid | Medium | Solution |
| 1537 | Get the Maximum Score | Hard | Solution |
| 1539 | Kth Missing Positive Number | Easy | Solution |
| 1542 | Find Longest Awesome Substring | Hard | Solution |
| 1544 | Make The String Great | Easy | Solution |
| 1545 | Find Kth Bit in Nth Binary String | Medium | Solution |
| 1546 | Maximum Number of Non-Overlapping Subarrays With Sum Equals Target | Medium | Solution |
| 1547 | Minimum Cost to Cut a Stick | Hard | Solution |
All rights reserved by github.com/lzl124631x. Contact me if you want to redistribute the code. No commercial use.
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