1207 Unique Number of Occurrences C++ Easy 1170 Compare Strings by Frequency of the Smallest Character C++ Easy 1030 Matrix Cells in Distance Order C++ Easy 1029 Two City Scheduling C++ Easy 1028 Recover a Tree From Preorder Traversal C++ Hard 1024 Video Stitching C++ Medium 993 Cousins in Binary Tree C++ Easy 991 Broken Calculator C++ Medium 990 Satisfiability of Equality Equations C++ Medium 989 Add to Array-Form of Integer C++ Easy 988 Smallest String Starting From Leaf C++ Medium 987 Vertical Order Traversal of a Binary Tree C++ Medium 986 Interval List Intersections C++ Medium 985 Sum of Even Numbers After Queries C++ Easy 984 String Without AAA or BBB C++ Easy 983 Minimum Cost For Tickets C++ Medium 981 Time Based Key-Value Store C++ Medium 980 Unique Paths III C++ Hard 979 Distribute Coins in Binary Tree C++ Medium 978 Longest Turbulent Subarray C++,Python Medium 977 Squares of a Sorted Array C++, Python Easy 976 Largest Perimeter Triangle C++, Python Easy 971 Flip Binary Tree To Match Preorder Traversal Python Medium 969 Pancake Sorting Python Medium 961 N-Repeated element in size 2N Array C++ Easy 958 Check Completeness of a Binary Tree Python Medium 951 Flip Equivalent Binary Trees Python Medium 950 Reveal Cards In Increasing Order Python Medium 941 Valid Mountain Array Python Easy 931 Minimum Falling Path Sum C++ Medium 922 Sort Array By Parity II C++ Easy 914 X of a Kind in a Deck of Cards Python Easy 905 Sort Array By Parity C++ Easy 876 Middle of the Linked List Python Easy 859 Buddy Strings C++ Easy 858 Mirror Reflection C++ Medium 852 Peak Index in a Mountain Array C++ Easy 849 Maximize Distance to Closest Person Python Easy 844 Backspace String Compare C++ Easy 837 Most Common Word C++ Easy 830 Positions of Large Groups Python Easy 804 Unique Morse Code Words C++ Easy 771 Jewels and Stones C++ Easy 747 Largest Number At Least Twice of Others Python Easy 746 Min Cost Climbing Stairs C++, Python Easy 721 Accounts Merge C++ Medium 717 1-bit and 2-bit Characters Python Easy 714 Best Time to Buy and Sell Stock with Transaction Fee C++ Medium 712 Minimum ASCII Delete Sum for Two Strings C++ Medium 695 Max Area of Island C++ Medium 687 Longest Univalue Path Python Easy 684 Redundant Connection Python Medium 674 Longest Continuous Increasing Subsequence Python Easy 671 Second Minimum Node In a Binary Tree Python Easy 665 Non-decreasing Array Python Easy 662 Maximum Width of Binary Tree Python Medium 661 Image Smoother Python Easy 655 Print Binary Tree Python Medium 652 Find Duplicate Subtrees Python Medium 647 Palindromic Substrings C++ Medium 643 Maximum Average Subarray I C++, Python Easy 628 Maximum Product of Three Numbers Python Easy 623 Add One Row to Tree Python Medium 581 Shortest Unsorted Continuous Subarray Python Easy 572 Subtree of Another Tree Python Easy 563 Binary Tree Tilt Python Easy 547 Friend Circles C++ Medium 543 Diameter of Binary Tree Python Easy 538 Convert BST to Greater Tree Python Easy 532 K-diff Pairs in an Array Python Easy 520 Detect Capital C++ Easy 518 Coin Change 2 C++ Medium 509 Fibonacci Number C++, Python Easy 477 Total Hamming Distance C++ Medium 463 Island Perimeter C++ Easy 450 DeleteNodeInABST Python Medium 449 Serialize and Deserialize BST Python Medium 438 Find all Anagrams in a string C++ Medium 437 Path Sum III Python Medium 418 SentenceScreenFitting ♥ C++ Easy 416 Partition Equal Subset Sum C++ Medium 415 Add Strings C++ Easy 414 Third Maximum Number C++, Python Easy 413 Arithmetic Slices C++ Medium 412 Fizz Buzz C++ Easy 410 Split Array Largest Sum C++ Hard 409 Longest Palindrome C++ Easy 406 Queue Reconstruction by Height C++ Medium 405 Convert a Number to Hexadecimal C++ Easy 404 Sum of Left Leaves C++, Python Easy 403 Frog Jump C++ Hard 402 Remove K Digits C++ Medium 401 Binary Watch C++ Easy 400 Nth Digit C++ Medium 399 Evaluate Division C++ Medium 398 Random Pick Index C++ Medium 397 Integer Replacement C++ Medium 396 Rotate Function C++ Easy 395 Longest Substring with At Least K Repeating Characters C++ Medium 394 Decode String C++ Medium 393 UTF-8 Validation C++ Medium 392 Is Subsequence C++ Medium 391 Perfect Rectangle C++ Hard 390 Elimination Game C++ Medium 389 Find the Difference C++ Easy 388 Longest Absolute File Path C++ Medium 387 First Unique Character in a String C++ Easy 386 Lexicographical Numbers C++ Medium 385 Mini Parser C++ Medium 384 Shuffle an Array C++ Medium 383 Ransom Note C++ Easy 382 Linked List Random Node C++ Medium 381 Insert Delete GetRandom O(1) - Duplicates allowed C++ Hard 380 Insert Delete GetRandom O(1) C++ Hard 377 Combination Sum IV C++ Medium 376 Wiggle Subsequence C++ Medium 371 Sum of Two Integers C++ Easy 367 Valid Perfect Square C++ Easy 357 Count Numbers with Unique Digits C++ Medium 350 Intersection of Two Arrays II C++ Easy 349 Intersection of Two Arrays C++ Easy 347 Top K Frequent Elements C++ Medium 345 Reverse Vowels of a String C++ Easy 344 Reverse String C++ Easy 343 Integer Break C++ Medium 342 Power of Four C++ Easy 341 Flatten Nested List Iterator C++ Medium 338 Counting Bits C++ Medium 337 House Robber III C++, Python Medium 336 Palindrome Pairs C++ Hard 334 Increasing Triplet Subsequence C++ Medium 332 Reconstruct Itinerary C++ Medium 331 Verify Preorder Serialization of a Binary Tree C++ Medium 330 Patching Array C++ Medium 329 Longest Increasing Path in a Matrix C++ Medium 328 Odd Even Linked List C++ Easy 327 Count of Range Sum C++ Hard 326 Power of Three C++ Easy 324 Wiggle Sort II C++ Medium 322 Coin Change C++ Medium 321 Create Maximum Number C++ Hard 319 Bulb Switcher C++ Medium 318 Maximum Product of Word Lengths C++ Medium 316 Remove Duplicate Letters C++ Hard 315 Count of Smaller Numbers After Self C++ Hard 313 Super Ugly Number C++ Medium 312 Burst Balloons C++ Hard 310 Minimum Height Trees C++ Medium 309 Best Time to Buy and Sell Stock with Cooldown C++ Medium 307 Range Sum Query - Mutable C++ Medium 306 Additive Number C++ Medium 304 Range Sum Query 2D - Immutable C++ Medium 303 Range Sum Query - Immutable C++ Easy 301 Remove Invalid Parentheses C++ Hard 300 Longest Increasing Subsequence C++ Medium 299 Bulls and Cows C++ Easy 297 Serialize and Deserialize Binary Tree C++ Medium 295 Find Median from Data Stream C++ Hard 292 Nim Game C++ Easy 290 Word Pattern C++ Easy 289 Game of Life C++ Medium 287 Find the Duplicate Number C++, Python Hard 285 Inorder Successor in BST ♥ Java Medium 284 Peeking Iterator C++ Medium 283 Move Zeroes C++ Easy 282 Expression Add Operators C++ Hard 279 Perfect Squares C++ Medium 278 First Bad Version C++, Java Easy 275 H-Index II C++ Medium 274 H-Index C++ Medium 273 Integer to English Words C++ Medium 268 Missing Number C++ Medium 264 Ugly Number II C++ Medium 263 Ugly Number C++ Easy 260 Single Number III C++ Medium 258 Add Digits C++ Easy 257 Binary Tree Paths C++ Easy 242 Valid Anagram C++, Java Easy 241 Different Ways to Add Parentheses C++, Python Medium 240 Search a 2D Matrix II C++, Java, Python Medium 239 Sliding Window Maximum C++ Hard 238 Product of Array Except Self C++ Medium 237 Delete Node in a Linked List C++ Easy 236 Lowest Common Ancestor of a Binary Tree C++, Java, Python Medium 235 Lowest Common Ancestor of a Binary Search Tree C++, Python Easy 234 Palindrome Linked List C++ Easy 233 Number of Digit One C++ Medium 232 Implement Queue using Stacks C++, Java Easy 231 Power of Two C++ Easy 230 Kth Smallest Element in a BST C++, Python Medium 229 Majority Element II C++ Medium 228 Summary Ranges C++ Easy 227 Basic Calculator II C++ Medium 226 Invert Binary Tree C++ Easy 225 Implement Stack using Queues C++, Java Medium 224 Basic Calculator C++ Medium 223 Rectangle Area C++ Easy 222 Count Complete Tree Nodes C++, Python Medium 221 Maximal Square C++ Medium 220 Contains Duplicate III C++, Python Medium 219 Contains Duplicate II C++, Python Easy 218 The Skyline Problem C++ Hard 217 Contains Duplicate C++ Easy 216 Combination Sum III C++ Medium 215 Kth Largest Element in an Array C++ Medium 214 Shortest Palindrome C++ Hard 213 House Robber II C++ Medium 212 Word Search II C++ Hard 211 Add and Search Word - Data structure design C++ Medium 210 Course Schedule II C++ Medium 209 Minimum Size Subarray Sum C++ Medium 208 Implement Trie (Prefix Tree) C++ Medium 207 Course Schedule C++ Medium 206 Reverse Linked List C++, Java Easy 205 Isomorphic Strings C++ Easy 204 Count Primes C++ Easy 203 Remove Linked List Elements C++ Easy 202 Happy Number C++, Python Easy 201 Bitwise AND of Numbers Range C++ Medium 200 Number of Islands C++, Python Medium 199 Binary Tree Right Side View C++ Medium 198 House Robber C++, Python Easy 191 Number of 1 Bits C++ Easy 190 Reverse Bits C++ Easy 189 Rotate Array C++, Java Easy 188 Best Time to Buy and Sell Stock IV C++ Hard 187 Repeated DNA Sequences C++ Medium 186 Reverse Words in a String II ♥ C++ Medium 179 Largest Number C++ Medium 174 Dungeon Game C++ Hard 173 Binary Search Tree Iterator C++, Java, Python Medium 172 Factorial Trailing Zeroes C++ Easy 171 Excel Sheet Column Number C++ Easy 170 Two Sum III - Data structure design ♥ C++ Easy 169 Majority Element C++ Easy 168 Excel Sheet Column Title C++ Easy 167 Two Sum II - Input array is sorted ♥ C++ Medium 166 Fraction to Recurring Decimal C++ Medium 165 Compare Version Numbers C++ Easy 164 Maximum Gap C++ Hard 163 Missing Ranges ♥ C++ Medium 162 Find Peak Element C++, Java Medium 161 One Edit Distance♥ C++ Medium 160 Intersection of Two Linked Lists C++ Easy 159 Longest Substring with At Most Two Distinct Characters ♥ C++ Hard 158 Read N Characters Given Read4 II - Call multiple times ♥ C++ Hard 157 Read N Characters Given Read4 ♥ C++ Easy 156 Binary Tree Upside Down ♥ C++ Medium 155 Min Stack C++, Java Easy 154 Find Minimum in Rotated Sorted Array II C++ Hard 153 Find Minimum in Rotated Sorted Array C++, Java Medium 152 Maximum Product Subarray C++ Medium 151 Reverse Words in a String C++, Java Medium 150 Evaluate Reverse Polish Notation C++ Medium 149 Max Points on a Line C++ Hard 148 Sort List C++, Python Medium 147 Insertion Sort List C++, Python Medium 146 LRU Cache C++, Java Hard 145 Binary Tree Postorder Traversal C++, Python Hard 144 Binary Tree Preorder Traversal C++, Java Medium 143 Reorder List C++, Python Medium 142 Linked List Cycle II C++, Python Medium 141 Linked List Cycle C++ Medium 140 Word Break II C++ Hard 139 Word Break C++ Medium 138 Copy List with Random Pointer C++, Python Hard 137 Single Number II C++ Medium 136 Single Number C++ Medium 135 Candy C++ Hard 134 Gas Station C++ Medium 133 Clone Graph C++ Medium 132 Palindrome Partitioning II C++ Hard 131 Palindrome Partitioning C++ Medium 130 Surrounded Regions C++ Medium 129 Sum Root to Leaf Numbers C++, Python Medium 128 Longest Consecutive Sequence C++ Hard 127 Word Ladder C++ Medium 126 Word Ladder II C++ Hard 125 Valid Palindrome C++, Java Easy 124 Binary Tree Maximum Path Sum C++, Java Hard 123 Best Time to Buy and Sell Stock III C++ Hard 122 Best Time to Buy and Sell Stock II C++ Medium 121 Best Time to Buy and Sell Stock C++ Medium 120 Triangle C++, Java Medium 119 Pascal's Triangle II C++ Easy 118 Pascal's Triangle C++ Easy 117 Populating Next Right Pointers in Each Node II C++, Python Hard 116 Populating Next Right Pointers in Each Node C++, Python Medium 115 Distinct Subsequences C++ Hard 114 Flatten Binary Tree to Linked List C++, Python Medium 113 Path Sum II C++, Python Medium 112 Path Sum C++ Easy 111 Minimum Depth of Binary Tree C++ Easy 110 Balanced Binary Tree C++, Java Easy 109 Convert Sorted List to Binary Search Tree C++ Medium 108 Convert Sorted Array to Binary Search Tree C++ Medium 107 Binary Tree Level Order Traversal II C++ Easy 106 Construct Binary Tree from Inorder and Postorder Traversal C++, Python Medium 105 Construct Binary Tree from Preorder and Inorder Traversal C++, Python Medium 104 Maximum Depth of Binary Tree C++, Java Easy 103 Binary Tree Zigzag Level Order Traversal C++, Python Medium 102 Binary Tree Level Order Traversal C++, Java Easy 101 Symmetric Tree C++ Easy 100 Same Tree C++ Easy 99 Recover Binary Search Tree C++ Hard 98 Validate Binary Search Tree C++, Java, Python Medium 97 Interleaving String C++ Hard 96 Unique Binary Search Trees C++, Python Medium 95 Unique Binary Search Trees II C++, Python Medium 94 Binary Tree Inorder Traversal C++ Medium 93 Restore IP Addresses C++ Medium 92 Reverse Linked List II C++, Java, Python Medium 91 Decode Ways C++ Medium 90 Subsets II C++, Java Medium 89 Gray Code C++ Medium 88 Merge Sorted Array C++ Easy 87 Scramble String C++ Hard 86 Partition List C++, Python Medium 85 Maximal Rectangle C++ Hard 84 Largest Rectangle in Histogram C++ Hard 83 Remove Duplicates from Sorted List C++ Easy 82 Remove Duplicates from Sorted List II C++, Python Medium 81 Search in Rotated Sorted Array II C++ Medium 80 Remove Duplicates from Sorted Array II C++ Medium 79 Word Search C++ Medium 78 Subsets C++, Java, Python Medium 77 Combinations C++ Medium 76 Minimum Window Substring C++ Hard 75 Sort Colors C++ Medium 74 Search a 2D Matrix C++, Java Medium 73 Set Matrix Zeroes C++ Medium 72 Edit Distance C++ Hard 71 Simplify Path C++ Medium 70 Climbing Stairs C++, Java Easy 69 Sqrt(x) C++ Medium 68 Text Justification C++ Hard 67 Add Binary C++ Easy 66 Plus One C++ Easy 65 Valid Number C++ Easy 64 Minimum Path Sum C++, Java Medium 63 Unique Paths II C++, Java Medium 62 Unique Paths C++, Java Medium 61 Rotate List C++ Medium 60 Permutation Sequence C++ Medium 59 Spiral Matrix II C++ Medium 58 Length of Last Word C++, Java Easy 57 Insert Interval C++ Hard 56 Merge Intervals C++ Hard 55 Jump Game C++ Medium 54 Spiral Matrix C++ Medium 53 Maximum Subarray C++ Medium 52 N-Queens II C++ Hard 51 N-Queens C++ Hard 50 "Pow(x, n)" C++, Java Medium 49 Group Anagrams C++ Medium 48 Rotate Image C++ Medium 47 Permutations II C++ Hard 46 Permutations C++ Medium 45 Jump Game II C++ Hard 44 Wildcard Matching C++ Hard 43 Multiply Strings C++ Medium 42 Trapping Rain Water C++ Hard 41 First Missing Positive C++ Hard 40 Combination Sum II C++ Medium 39 Combination Sum C++ Medium 38 Count and Say C++, Java Easy 37 Sudoku Solver C++ Hard 36 Valid Sudoku C++ Easy 35 Search Insert Position C++, Java Medium 34 Search for a Range C++, Java Medium 33 Search in Rotated Sorted Array C++, Java Hard 32 Longest Valid Parentheses C++ Hard 31 Next Permutation C++ Medium 30 Substring with Concatenation of All Words C++ Hard 29 Divide Two Integers C++ Medium 28 Implement strStr() C++, Java Easy 27 Remove Element C++ Easy 26 Remove Duplicates from Sorted Array C++, Java Easy 25 Reverse Nodes in k-Group C++ Hard 24 Swap Nodes in Pairs C++ Medium 23 Merge k Sorted Lists C++ Hard 22 Generate Parentheses C++ Medium 21 Merge Two Sorted Lists C++ Easy 20 Valid Parentheses C++ Easy 19 Remove Nth Node From End of List C++, Python Easy 18 4Sum C++ Medium 17 Letter Combinations of a Phone Number C++ Medium 16 3Sum Closest C++ Medium 15 3Sum C++ Medium 14 Longest Common Prefix C++ Easy 13 Roman to Integer C++ Easy 12 Integer to Roman C++ Medium 11 Container With Most Water C++ Medium 10 Regular Expression Matching C++ Hard 9 Palindrome Number C++, Java Easy 8 String to Integer (atoi) C++ Easy 7 Reverse Integer C++ Easy 6 ZigZag Conversion C++ Easy 5 Longest Palindromic Substring C++ Medium 4 Median of Two Sorted Arrays C++ Hard 3 Longest Substring Without Repeating Characters C++ Medium 2 Add Two Numbers C++ Medium 1 Two Sum C++, Go Easy