| ID | Title | Acceptance | Difficulty | Frequency |
|---|
| 425 | Word Squares | 47.7% | Hard | 1.373784 |
| 146 | LRU Cache | 33.2% | Medium | 1.223338 |
| 352 | Data Stream as Disjoint Intervals | 47.3% | Hard | 1.072892 |
| 450 | Delete Node in a BST | 43.1% | Medium | 0.922445 |
| 362 | Design Hit Counter | 63.7% | Medium | 0.894460 |
| 1 | Two Sum | 45.6% | Easy | 0.867108 |
| 554 | Brick Wall | 50.0% | Medium | 0.848711 |
| 23 | Merge k Sorted Lists | 40.2% | Hard | 0.744432 |
| 253 | Meeting Rooms II | 45.7% | Medium | 0.593986 |
| 403 | Frog Jump | 39.7% | Hard | 0.584717 |
| 200 | Number of Islands | 46.8% | Medium | 0.449298 |
| 297 | Serialize and Deserialize Binary Tree | 47.5% | Hard | 0.414186 |
| 56 | Merge Intervals | 39.3% | Medium | 0.406102 |
| 394 | Decode String | 50.0% | Medium | 0.379295 |
| 227 | Basic Calculator II | 36.9% | Medium | 0.370982 |
| 415 | Add Strings | 47.5% | Easy | 0.356560 |
| 17 | Letter Combinations of a Phone Number | 46.8% | Medium | 0.335147 |
| 73 | Set Matrix Zeroes | 43.1% | Medium | 0.333601 |
| 33 | Search in Rotated Sorted Array | 34.5% | Medium | 0.330352 |
| 54 | Spiral Matrix | 34.1% | Medium | 0.316376 |
| 53 | Maximum Subarray | 46.5% | Easy | 0.312350 |
| 1242 | Web Crawler Multithreaded | 45.9% | Medium | 0.309617 |
| 706 | Design HashMap | 61.3% | Easy | 0.306079 |
| 636 | Exclusive Time of Functions | 51.9% | Medium | 0.292582 |
| 692 | Top K Frequent Words | 51.8% | Medium | 0.276682 |
| 599 | Minimum Index Sum of Two Lists | 50.7% | Easy | 0.272347 |
| 173 | Binary Search Tree Iterator | 56.6% | Medium | 0.267662 |
| 20 | Valid Parentheses | 39.0% | Easy | 0.265897 |
| 127 | Word Ladder | 29.6% | Medium | 0.257624 |
| 126 | Word Ladder II | 22.1% | Hard | 0.255039 |
| 75 | Sort Colors | 47.3% | Medium | 0.248055 |
| 535 | Encode and Decode TinyURL | 79.9% | Medium | 0.237403 |
| 545 | Boundary of Binary Tree | 38.9% | Medium | 0.235382 |
| 1188 | Design Bounded Blocking Queue | 70.5% | Medium | 0.233007 |
| 722 | Remove Comments | 34.6% | Medium | 0.229733 |
| 1190 | Reverse Substrings Between Each Pair of Parentheses | 61.5% | Medium | 0.221284 |
| 236 | Lowest Common Ancestor of a Binary Tree | 45.7% | Medium | 0.208266 |
| 232 | Implement Queue using Stacks | 49.6% | Easy | 0.206154 |
| 37 | Sudoku Solver | 43.6% | Hard | 0.203090 |
| 138 | Copy List with Random Pointer | 36.4% | Medium | 0.201770 |
| 426 | Convert Binary Search Tree to Sorted Doubly Linked List | 59.1% | Medium | 0.199332 |
| 42 | Trapping Rain Water | 48.9% | Hard | 0.193630 |
| 206 | Reverse Linked List | 62.5% | Easy | 0.191793 |
| 46 | Permutations | 63.5% | Medium | 0.188166 |
| 438 | Find All Anagrams in a String | 43.3% | Medium | 0.185647 |
| 380 | Insert Delete GetRandom O(1) | 47.5% | Medium | 0.182198 |
| 1212 | Team Scores in Football Tournament | 55.8% | Medium | 0.177280 |
| 238 | Product of Array Except Self | 60.1% | Medium | 0.176446 |
| 230 | Kth Smallest Element in a BST | 60.2% | Medium | 0.175865 |
| 2 | Add Two Numbers | 33.9% | Medium | 0.170862 |
| 43 | Multiply Strings | 33.9% | Medium | 0.170616 |
| 609 | Find Duplicate File in System | 59.5% | Medium | 0.169718 |
| 349 | Intersection of Two Arrays | 62.5% | Easy | 0.167138 |
| 715 | Range Module | 38.5% | Hard | 0.163629 |
| 121 | Best Time to Buy and Sell Stock | 50.5% | Easy | 0.158900 |
| 141 | Linked List Cycle | 41.1% | Easy | 0.158279 |
| 139 | Word Break | 40.1% | Medium | 0.152602 |
| 314 | Binary Tree Vertical Order Traversal | 45.3% | Medium | 0.151486 |
| 21 | Merge Two Sorted Lists | 53.5% | Easy | 0.151106 |
| 863 | All Nodes Distance K in Binary Tree | 55.4% | Medium | 0.143157 |
| 34 | Find First and Last Position of Element in Sorted Array | 36.2% | Medium | 0.142575 |
| 208 | Implement Trie (Prefix Tree) | 49.4% | Medium | 0.136585 |
| 10 | Regular Expression Matching | 26.8% | Hard | 0.136322 |
| 5 | Longest Palindromic Substring | 29.5% | Medium | 0.136315 |
| 1044 | Longest Duplicate Substring | 31.9% | Hard | 0.135137 |
| 195 | Tenth Line | 33.0% | Easy | 0.132938 |
| 4 | Median of Two Sorted Arrays | 29.6% | Hard | 0.131624 |
| 3 | Longest Substring Without Repeating Characters | 30.4% | Medium | 0.131471 |
| 214 | Shortest Palindrome | 29.8% | Hard | 0.130265 |
| 958 | Check Completeness of a Binary Tree | 52.1% | Medium | 0.128844 |
| 694 | Number of Distinct Islands | 56.0% | Medium | 0.125163 |
| 163 | Missing Ranges | 24.3% | Medium | 0.118218 |
| 207 | Course Schedule | 43.1% | Medium | 0.117257 |
| 160 | Intersection of Two Linked Lists | 40.6% | Easy | 0.115856 |
| 101 | Symmetric Tree | 46.8% | Easy | 0.115838 |
| 503 | Next Greater Element II | 56.5% | Medium | 0.112427 |
| 344 | Reverse String | 68.5% | Easy | 0.111449 |
| 965 | Univalued Binary Tree | 67.7% | Easy | 0.111324 |
| 412 | Fizz Buzz | 62.3% | Easy | 0.108914 |
| 204 | Count Primes | 31.5% | Easy | 0.107558 |
| 295 | Find Median from Data Stream | 44.3% | Hard | 0.105021 |
| 273 | Integer to English Words | 27.1% | Hard | 0.103809 |
| 417 | Pacific Atlantic Water Flow | 41.1% | Medium | 0.100083 |
| 12 | Integer to Roman | 55.1% | Medium | 0.099818 |
| 13 | Roman to Integer | 55.7% | Easy | 0.098847 |
| 71 | Simplify Path | 32.6% | Medium | 0.097543 |
| 1236 | Web Crawler | 64.3% | Medium | 0.095310 |
| 215 | Kth Largest Element in an Array | 55.4% | Medium | 0.093264 |
| 794 | Valid Tic-Tac-Toe State | 32.6% | Medium | 0.092231 |
| 243 | Shortest Word Distance | 61.0% | Easy | 0.089522 |
| 652 | Find Duplicate Subtrees | 50.2% | Medium | 0.089079 |
| 109 | Convert Sorted List to Binary Search Tree | 47.7% | Medium | 0.087011 |
| 449 | Serialize and Deserialize BST | 52.0% | Medium | 0.086964 |
| 116 | Populating Next Right Pointers in Each Node | 45.2% | Medium | 0.086366 |
| 114 | Flatten Binary Tree to Linked List | 49.3% | Medium | 0.081372 |
| 242 | Valid Anagram | 56.9% | Easy | 0.080930 |
| 29 | Divide Two Integers | 16.4% | Medium | 0.079964 |
| 57 | Insert Interval | 33.5% | Hard | 0.079305 |
| 341 | Flatten Nested List Iterator | 52.9% | Medium | 0.077633 |
| 49 | Group Anagrams | 56.9% | Medium | 0.074346 |
| 721 | Accounts Merge | 48.8% | Medium | 0.073494 |
| 155 | Min Stack | 44.5% | Easy | 0.073402 |
| 505 | The Maze II | 47.7% | Medium | 0.071331 |
| 205 | Isomorphic Strings | 39.8% | Easy | 0.070056 |
| 136 | Single Number | 65.5% | Easy | 0.069380 |
| 284 | Peeking Iterator | 45.7% | Medium | 0.068676 |
| 289 | Game of Life | 54.5% | Medium | 0.067564 |
| 199 | Binary Tree Right Side View | 54.1% | Medium | 0.067481 |
| 560 | Subarray Sum Equals K | 43.9% | Medium | 0.066366 |
| 1197 | Minimum Knight Moves | 36.1% | Medium | 0.065621 |
| 15 | 3Sum | 26.8% | Medium | 0.064469 |
| 51 | N-Queens | 46.6% | Hard | 0.064021 |
| 1170 | Compare Strings by Frequency of the Smallest Character | 58.7% | Easy | 0.060901 |
| 305 | Number of Islands II | 40.1% | Hard | 0.060078 |
| 355 | Design Twitter | 30.3% | Medium | 0.058240 |
| 45 | Jump Game II | 30.6% | Hard | 0.058223 |
| 741 | Cherry Pickup | 33.9% | Hard | 0.056512 |
| 41 | First Missing Positive | 32.0% | Hard | 0.056273 |
| 32 | Longest Valid Parentheses | 28.4% | Hard | 0.055631 |
| 128 | Longest Consecutive Sequence | 45.1% | Hard | 0.055274 |
| 7 | Reverse Integer | 25.8% | Easy | 0.054824 |
| 76 | Minimum Window Substring | 34.6% | Hard | 0.054733 |
| 836 | Rectangle Overlap | 48.6% | Easy | 0.053712 |
| 894 | All Possible Full Binary Trees | 75.2% | Medium | 0.052436 |
| 94 | Binary Tree Inorder Traversal | 63.3% | Medium | 0.052376 |
| 767 | Reorganize String | 48.7% | Medium | 0.052163 |
| 14 | Longest Common Prefix | 35.4% | Easy | 0.051846 |
| 209 | Minimum Size Subarray Sum | 38.2% | Medium | 0.051462 |
| 235 | Lowest Common Ancestor of a Binary Search Tree | 49.9% | Easy | 0.050282 |
| 695 | Max Area of Island | 62.7% | Medium | 0.049807 |
| 518 | Coin Change 2 | 50.2% | Medium | 0.049195 |
| 445 | Add Two Numbers II | 54.5% | Medium | 0.048435 |
| 125 | Valid Palindrome | 36.7% | Easy | 0.047702 |
| 876 | Middle of the Linked List | 68.4% | Easy | 0.046728 |
| 240 | Search a 2D Matrix II | 43.2% | Medium | 0.046476 |
| 283 | Move Zeroes | 57.8% | Easy | 0.045195 |
| 36 | Valid Sudoku | 48.7% | Medium | 0.044523 |
| 529 | Minesweeper | 59.1% | Medium | 0.044255 |
| 268 | Missing Number | 51.7% | Easy | 0.043089 |
| 184 | Department Highest Salary | 36.7% | Medium | 0.041672 |
| 532 | K-diff Pairs in an Array | 31.6% | Easy | 0.041672 |
| 92 | Reverse Linked List II | 38.8% | Medium | 0.041073 |
| 1008 | Construct Binary Search Tree from Preorder Traversal | 78.4% | Medium | 0.041026 |
| 79 | Word Search | 35.6% | Medium | 0.040808 |
| 212 | Word Search II | 34.9% | Hard | 0.038811 |
| 113 | Path Sum II | 46.7% | Medium | 0.038577 |
| 24 | Swap Nodes in Pairs | 50.4% | Medium | 0.038266 |
| 19 | Remove Nth Node From End of List | 35.2% | Medium | 0.037049 |
| 322 | Coin Change | 35.5% | Medium | 0.035696 |
| 973 | K Closest Points to Origin | 63.8% | Medium | 0.035550 |
| 59 | Spiral Matrix II | 53.9% | Medium | 0.035187 |
| 105 | Construct Binary Tree from Preorder and Inorder Traversal | 48.8% | Medium | 0.034667 |
| 543 | Diameter of Binary Tree | 48.4% | Easy | 0.032708 |
| 350 | Intersection of Two Arrays II | 51.4% | Easy | 0.032128 |
| 150 | Evaluate Reverse Polish Notation | 36.3% | Medium | 0.031526 |
| 55 | Jump Game | 34.6% | Medium | 0.030985 |
| 38 | Count and Say | 44.6% | Easy | 0.030956 |
| 179 | Largest Number | 28.8% | Medium | 0.030930 |
| 151 | Reverse Words in a String | 21.9% | Medium | 0.030683 |
| 347 | Top K Frequent Elements | 61.2% | Medium | 0.029662 |
| 496 | Next Greater Element I | 63.8% | Easy | 0.029462 |
| 456 | 132 Pattern | 28.9% | Medium | 0.029306 |
| 169 | Majority Element | 58.7% | Easy | 0.029058 |
| 62 | Unique Paths | 54.1% | Medium | 0.028537 |
| 938 | Range Sum of BST | 81.3% | Easy | 0.027755 |
| 437 | Path Sum III | 47.2% | Medium | 0.027085 |
| 796 | Rotate String | 49.6% | Easy | 0.027010 |
| 103 | Binary Tree Zigzag Level Order Traversal | 48.3% | Medium | 0.026991 |
| 1305 | All Elements in Two Binary Search Trees | 76.1% | Medium | 0.026282 |
| 98 | Validate Binary Search Tree | 27.8% | Medium | 0.026187 |
| 91 | Decode Ways | 24.7% | Medium | 0.023662 |
| 26 | Remove Duplicates from Sorted Array | 45.1% | Easy | 0.023645 |
| 844 | Backspace String Compare | 46.4% | Easy | 0.023555 |
| 622 | Design Circular Queue | 43.8% | Medium | 0.022460 |
| 981 | Time Based Key-Value Store | 53.1% | Medium | 0.022260 |
| 152 | Maximum Product Subarray | 31.7% | Medium | 0.022176 |
| 221 | Maximal Square | 37.7% | Medium | 0.022108 |
| 112 | Path Sum | 41.2% | Easy | 0.021701 |
| 300 | Longest Increasing Subsequence | 42.6% | Medium | 0.020893 |
| 9 | Palindrome Number | 48.4% | Easy | 0.018837 |
| 88 | Merge Sorted Array | 39.4% | Easy | 0.018667 |
| 617 | Merge Two Binary Trees | 74.1% | Easy | 0.018496 |
| 239 | Sliding Window Maximum | 43.0% | Hard | 0.017685 |
| 50 | Pow(x;n) | 30.3% | Medium | 0.017036 |
| 402 | Remove K Digits | 28.4% | Medium | 0.016863 |
| 340 | Longest Substring with At Most K Distinct Characters | 44.1% | Hard | 0.016122 |
| 217 | Contains Duplicate | 56.0% | Easy | 0.015106 |
| 707 | Design Linked List | 24.5% | Medium | 0.015054 |
| 102 | Binary Tree Level Order Traversal | 54.6% | Medium | 0.014477 |
| 107 | Binary Tree Level Order Traversal II | 53.5% | Easy | 0.014395 |
| 315 | Count of Smaller Numbers After Self | 41.5% | Hard | 0.014352 |
| 44 | Wildcard Matching | 24.7% | Hard | 0.013703 |
| 70 | Climbing Stairs | 47.8% | Easy | 0.013494 |
| 122 | Best Time to Buy and Sell Stock II | 57.0% | Easy | 0.013351 |
| 1047 | Remove All Adjacent Duplicates In String | 68.6% | Easy | 0.013059 |
| 108 | Convert Sorted Array to Binary Search Tree | 57.9% | Easy | 0.012453 |
| 287 | Find the Duplicate Number | 55.5% | Medium | 0.012335 |
| 11 | Container With Most Water | 50.8% | Medium | 0.012214 |
| 986 | Interval List Intersections | 67.3% | Medium | 0.011969 |
| 119 | Pascal’s Triangle II | 49.0% | Easy | 0.011894 |
| 210 | Course Schedule II | 40.7% | Medium | 0.011869 |
| 264 | Ugly Number II | 42.0% | Medium | 0.011604 |
| 117 | Populating Next Right Pointers in Each Node II | 39.1% | Medium | 0.011389 |
| 819 | Most Common Word | 44.8% | Easy | 0.010269 |
| 905 | Sort Array By Parity | 74.1% | Easy | 0.009603 |
| 621 | Task Scheduler | 50.1% | Medium | 0.009334 |
| 28 | Implement strStr() | 34.5% | Easy | 0.008850 |
| 8 | String to Integer (atoi) | 15.4% | Medium | 0.008513 |
| 153 | Find Minimum in Rotated Sorted Array | 45.1% | Medium | 0.008430 |
| 977 | Squares of a Sorted Array | 72.1% | Easy | 0.003891 |
| 67 | Add Binary | 45.2% | Easy | 0.003735 |
| 140 | Word Break II | 32.6% | Hard | 0.002707 |
| 1380 | Lucky Numbers in a Matrix | 71.5% | Easy | 0 |
| 1410 | HTML Entity Parser | 54.0% | Medium | 0 |
