| 1 |
Two Sum |
Solution |
| 2 |
Add Two Numbers |
Solution |
| 3 |
Longest Substring Without Repeating Characters |
Solution |
| 5 |
Longest Palindromic Substring |
Solution |
| 6 |
ZigZag Conversion |
Solution |
| 7 |
Reverse Integer |
Solution |
| 8 |
String to Integer (atoi) |
Solution |
| 9 |
Palindrome Number |
Solution |
| 11 |
Container With Most Water |
Solution |
| 13 |
Roman to Integer |
Solution |
| 14 |
Longest Common Prefix |
Solution |
| 15 |
3Sum |
Solution |
| 17 |
Letter Combinations of a Phone Number |
Solution |
| 19 |
Remove Nth Node From End of List |
Solution |
| 20 |
Valid Parentheses |
Solution |
| 21 |
Merge Two Sorted Lists |
Solution |
| 22 |
Generate Parentheses |
Solution |
| 23 |
Merge k Sorted Lists |
Solution |
| 25 |
Reverse Nodes in k-Group |
Solution |
| 26 |
Remove Duplicates from Sorted Array |
Solution |
| 27 |
Remove Element |
Solution |
| 28 |
Implement strStr() |
Solution |
| 29 |
Divide Two Integers |
Solution |
| 32 |
Longest Valid Parentheses |
Solution |
| 33 |
Search in Rotated Sorted Array |
Solution |
| 34 |
Find First and Last Position of Element in Sorted Array |
Solution |
| 37 |
Sudoku Solver |
Solution |
| 39 |
Combination Sum |
Solution |
| 40 |
Combination Sum II |
Solution |
| 41 |
First Missing Positive |
Solution |
| 42 |
Trapping Rain Water |
Solution |
| 43 |
Multiply Strings |
Solution |
| 45 |
Jump Game II |
Solution |
| 46 |
Permutations |
Solution |
| 47 |
Permutations II |
Solution |
| 48 |
Rotate Image |
Solution |
| 49 |
Group Anagrams |
Solution |
| 50 |
Pow(x, n) |
Solution |
| 51 |
N-Queens |
Solution |
| 53 |
Maximum Subarray |
Solution |
| 53 |
Maximum Subarray |
Solution |
| 54 |
Spiral Matrix |
Solution |
| 55 |
Jump Game |
Solution |
| 56 |
Merge Intervals |
Solution |
| 57 |
Insert Interval |
Solution |
| 58 |
Length of Last Word |
Solution |
| 59 |
Spiral Matrix II |
Solution |
| 61 |
Rotate List |
Solution |
| 62 |
Unique Paths |
Solution |
| 63 |
Unique Paths II |
Solution |
| 64 |
Minimum Path Sum |
Solution |
| 66 |
Plus One |
Solution |
| 67 |
Add Binary |
Solution |
| 71 |
Simplify Path |
Solution |
| 73 |
Set Matrix Zeroes |
Solution |
| 74 |
Search a 2D Matrix |
Solution |
| 75 |
Sort Colors |
Solution |
| 76 |
Minimum Window Substring |
Solution |
| 77 |
Combinations |
Solution |
| 78 |
Subsets |
Solution |
| 80 |
Remove Duplicates from Sorted Array II |
Solution |
| 81 |
Search in Rotated Sorted Array II |
Solution |
| 82 |
Remove Duplicates from Sorted List II |
Solution |
| 83 |
Remove Duplicates from Sorted List |
Solution |
| 84 |
Largest Rectangle in Histogram |
Solution |
| 85 |
Maximal Rectangle |
Solution |
| 86 |
Partition List |
Solution |
| 88 |
Merge Sorted Array |
Solution |
| 90 |
Subsets II |
Solution |
| 92 |
Reverse Linked List II |
Solution |
| 93 |
Restore IP Addresses |
Solution |
| 94 |
Binary Tree Inorder Traversal |
Solution |
| 95 |
Unique Binary Search Trees II |
Solution |
| 96 |
Unique Binary Search Trees |
Solution |
| 98 |
Validate Binary Search Tree |
Solution |
| 100 |
Same Tree |
Solution |
| 101 |
Symmetric Tree |
Solution |
| 102 |
Binary Tree Level Order Traversal |
Solution |
| 103 |
Binary Tree Zigzag Level Order Traversal |
Solution |
| 104 |
Maximum Depth of Binary Tree |
Solution |
| 105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Solution |
| 106 |
Construct Binary Tree from Inorder and Postorder Traversal |
Solution |
| 107 |
Binary Tree Level Order Traversal II |
Solution |
| 108 |
Convert Sorted Array 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 |
| 118 |
Pascal's Triangle |
Solution |
| 119 |
Pascal's Triangle II |
Solution |
| 121 |
Best Time to Buy and Sell Stock |
Solution |
| 122 |
Best Time to Buy and Sell Stock II |
Solution |
| 123 |
Best Time to Buy and Sell Stock III |
Solution |
| 124 |
Binary Tree Maximum Path Sum |
Solution |
| 125 |
Valid Palindrome |
Solution |
| 128 |
Longest Consecutive Sequence |
Solution |
| 131 |
Palindrome Partitioning |
Solution |
| 134 |
Gas Station |
Solution |
| 135 |
Candy |
Solution |
| 139 |
Word Break |
Solution |
| 141 |
Linked List Cycle |
Solution |
| 142 |
Linked List Cycle II |
Solution |
| 144 |
Binary Tree Preorder Traversal |
Solution |
| 145 |
Binary Tree Postorder Traversal |
Solution |
| 146 |
LRU Cache |
Solution |
| 148 |
Sort List |
Solution |
| 150 |
Evaluate Reverse Polish Notation |
Solution |
| 151 |
Reverse Words in a String |
Solution |
| 152 |
Maximum Product Subarray |
Solution |
| 153 |
Find Minimum in Rotated Sorted Array |
Solution |
| 154 |
Find Minimum in Rotated Sorted Array II |
Solution |
| 160 |
Intersection of Two Linked Lists |
Solution |
| 162 |
Find Peak Element |
Solution |
| 167 |
Two Sum II - Input Array Is Sorted |
Solution |
| 168 |
Excel Sheet Column Title |
Solution |
| 171 |
Excel Sheet Column Number |
Solution |
| 172 |
Factorial Trailing Zeroes |
Solution |
| 173 |
Binary Search Tree Iterator |
Solution |
| 179 |
Largest Number |
Solution |
| 187 |
Repeated DNA Sequences |
Solution |
| 188 |
Best Time to Buy and Sell Stock IV |
Solution |
| 189 |
Rotate Array |
Solution |
| 190 |
Reverse Bits |
Solution |
| 191 |
Number of 1 Bits |
Solution |
| 199 |
Binary Tree Right Side View |
Solution |
| 200 |
Number of Islands |
Solution |
| 202 |
Happy Number |
Solution |
| 203 |
Remove Linked List Elements |
Solution |
| 205 |
Isomorphic Strings |
Solution |
| 206 |
Reverse Linked List |
Solution |
| 207 |
Course Schedule |
Solution |
| 208 |
Implement Trie (Prefix Tree) |
Solution |
| 209 |
Minimum Size Subarray Sum |
Solution |
| 211 |
Design Add and Search Words Data Structure |
Solution |
| 214 |
Shortest Palindrome |
Solution |
| 215 |
Kth Largest Element in an Array |
Solution |
| 216 |
Combination Sum III |
Solution |
| 217 |
Contains Duplicate |
Solution |
| 219 |
Contains Duplicate II |
Solution |
| 220 |
Contains Duplicate III |
Solution |
| 221 |
Maximal Square |
Solution |
| 222 |
Count Complete Tree Nodes |
Solution |
| 224 |
Basic Calculator |
Solution |
| 225 |
Implement Stack using Queues |
Solution |
| 227 |
Basic Calculator II |
Solution |
| 230 |
Kth Smallest Element in a BST |
Solution |
| 231 |
Power of Two |
Solution |
| 232 |
Implement Queue using Stacks |
Solution |
| 234 |
Palindrome Linked List |
Solution |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
Solution |
| 236 |
Lowest Common Ancestor of a Binary Tree |
Solution |
| 238 |
Product of Array Except Self |
Solution |
| 239 |
Sliding Window Maximum |
Solution |
| 242 |
Valid Anagram |
Solution |
| 252 |
Meeting Rooms |
Solution |
| 253 |
Meeting Rooms II |
Solution |
| 254 |
Factor Combinations |
Solution |
| 257 |
Binary Tree Paths |
Solution |
| 258 |
Add Digits |
Solution |
| 263 |
Ugly Number |
Solution |
| 274 |
H-Index |
Solution |
| 278 |
First Bad Version |
Solution |
| 283 |
Move Zeroes |
Solution |
| 285 |
Inorder Successor in BST |
Solution |
| 287 |
Find the Duplicate Number |
Solution |
| 289 |
Game of Life |
Solution |
| 290 |
Word Pattern |
Solution |
| 295 |
Find Median from Data Stream |
Solution |
| 297 |
Serialize and Deserialize Binary Tree |
Solution |
| 299 |
Bulls and Cows |
Solution |
| 300 |
Longest Increasing Subsequence |
Solution |
| 303 |
Range Sum Query - Immutable |
Solution |
| 304 |
Range Sum Query 2D - Immutable |
Solution |
| 319 |
Bulb Switcher |
Solution |
| 324 |
Wiggle Sort II |
Solution |
| 326 |
Power of Three |
Solution |
| 328 |
Odd Even Linked List |
Solution |
| 331 |
Verify Preorder Serialization of a Binary Tree |
Solution |
| 334 |
Increasing Triplet Subsequence |
Solution |
| 341 |
Flatten Nested List Iterator |
Solution |
| 342 |
Power of Four |
Solution |
| 344 |
Reverse String |
Solution |
| 345 |
Reverse Vowels of a String |
Solution |
| 347 |
Top K Frequent Elements |
Solution |
| 349 |
Intersection of Two Arrays |
Solution |
| 350 |
Intersection of Two Arrays II |
Solution |
| 376 |
Wiggle Subsequence |
Solution |
| 380 |
Insert Delete GetRandom O(1) |
Solution |
| 383 |
Ransom Note |
Solution |
| 385 |
Mini Parser |
Solution |
| 387 |
First Unique Character in a String |
Solution |
| 388 |
Longest Absolute File Path |
Solution |
| 389 |
Find the Difference |
Solution |
| 392 |
Is Subsequence |
Solution |
| 394 |
Decode String |
Solution |
| 395 |
Longest Substring with At Least K Repeating Characters |
Solution |
| 396 |
Rotate Function |
Solution |
| 405 |
Convert a Number to Hexadecimal |
Solution |
| 406 |
Queue Reconstruction by Height |
Solution |
| 412 |
Fizz Buzz |
Solution |
| 414 |
Third Maximum Number |
Solution |
| 415 |
Add Strings |
Solution |
| 419 |
Battleships in a Board |
Solution |
| 424 |
Longest Repeating Character Replacement |
Solution |
| 429 |
N-ary Tree Level Order Traversal |
Solution |
| 434 |
Number of Segments in a String |
Solution |
| 438 |
Find All Anagrams in a String |
Solution |
| 442 |
Find All Duplicates in an Array |
Solution |
| 445 |
Add Two Numbers II |
Solution |
| 448 |
Find All Numbers Disappeared in an Array |
Solution |
| 449 |
Serialize and Deserialize BST |
Solution |
| 451 |
Sort Characters By Frequency |
Solution |
| 452 |
Minimum Number of Arrows to Burst Balloons |
Solution |
| 454 |
4Sum II |
Solution |
| 455 |
Assign Cookies |
Solution |
| 459 |
Repeated Substring Pattern |
Solution |
| 460 |
LFU Cache |
Solution |
| 461 |
Hamming Distance |
Solution |
| 467 |
Unique Substrings in Wraparound String |
Solution |
| 475 |
Heaters |
Solution |
| 476 |
Number Complement |
Solution |
| 477 |
Total Hamming Distance |
Solution |
| 480 |
Sliding Window Median |
Solution |
| 482 |
License Key Formatting |
Solution |
| 485 |
Max Consecutive Ones |
Solution |
| 491 |
Increasing Subsequences |
Solution |
| 495 |
Teemo Attacking |
Solution |
| 496 |
Next Greater Element I |
Solution |
| 498 |
Diagonal Traverse |
Solution |
| 500 |
Keyboard Row |
Solution |
| 503 |
Next Greater Element II |
Solution |
| 504 |
Base 7 |
Solution |
| 506 |
Relative Ranks |
Solution |
| 507 |
Perfect Number |
Solution |
| 508 |
Most Frequent Subtree Sum |
Solution |
| 513 |
Find Bottom Left Tree Value |
Solution |
| 515 |
Find Largest Value in Each Tree Row |
Solution |
| 520 |
Detect Capital |
Solution |
| 523 |
Continuous Subarray Sum |
Solution |
| 524 |
Longest Word in Dictionary through Deleting |
Solution |
| 525 |
Contiguous Array |
Solution |
| 528 |
Random Pick with Weight |
Solution |
| 530 |
Minimum Absolute Difference in BST |
Solution |
| 532 |
K-diff Pairs in an Array |
Solution |
| 537 |
Complex Number Multiplication |
Solution |
| 538 |
Convert BST to Greater Tree |
Solution |
| 539 |
Minimum Time Difference |
Solution |
| 541 |
Reverse String II |
Solution |
| 543 |
Diameter of Binary Tree |
Solution |
| 551 |
Student Attendance Record I |
Solution |
| 554 |
Brick Wall |
Solution |
| 557 |
Reverse Words in a String III |
Solution |
| 559 |
Maximum Depth of N-ary Tree |
Solution |
| 560 |
Subarray Sum Equals K |
Solution |
| 563 |
Binary Tree Tilt |
Solution |
| 566 |
Reshape the Matrix |
Solution |
| 567 |
Permutation in String |
Solution |
| 572 |
Subtree of Another Tree |
Solution |
| 575 |
Distribute Candies |
Solution |
| 581 |
Shortest Unsorted Continuous Subarray |
Solution |
| 589 |
N-ary Tree Preorder Traversal |
Solution |
| 590 |
N-ary Tree Postorder Traversal |
Solution |
| 592 |
Fraction Addition and Subtraction |
Solution |
| 594 |
Longest Harmonious Subsequence |
Solution |
| 598 |
Range Addition II |
Solution |
| 599 |
Minimum Index Sum of Two Lists |
Solution |
| 605 |
Can Place Flowers |
Solution |
| 606 |
Construct String from Binary Tree |
Solution |
| 609 |
Find Duplicate File in System |
Solution |
| 611 |
Valid Triangle Number |
Solution |
| 617 |
Merge Two Binary Trees |
Solution |
| 621 |
Task Scheduler |
Solution |
| 628 |
Maximum Product of Three Numbers |
Solution |
| 633 |
Sum of Square Numbers |
Solution |
| 637 |
Average of Levels in Binary Tree |
Solution |
| 643 |
Maximum Average Subarray I |
Solution |
| 645 |
Set Mismatch |
Solution |
| 646 |
Maximum Length of Pair Chain |
Solution |
| 647 |
Palindromic Substrings |
Solution |
| 652 |
Find Duplicate Subtrees |
Solution |
| 654 |
Maximum Binary Tree |
Solution |
| 657 |
Robot Return to Origin |
Solution |
| 658 |
Find K Closest Elements |
Solution |
| 662 |
Maximum Width of Binary Tree |
Solution |
| 665 |
Non-decreasing Array |
Solution |
| 669 |
Trim a Binary Search Tree |
Solution |
| 670 |
Maximum Swap |
Solution |
| 671 |
Second Minimum Node In a Binary Tree |
Solution |
| 674 |
Longest Continuous Increasing Subsequence |
Solution |
| 678 |
Valid Parenthesis String |
Solution |
| 680 |
Valid Palindrome II |
Solution |
| 682 |
Baseball Game |
Solution |
| 686 |
Repeated String Match |
Solution |
| 687 |
Longest Univalue Path |
Solution |
| 692 |
Top K Frequent Words |
Solution |
| 693 |
Binary Number with Alternating Bits |
Solution |
| 696 |
Count Binary Substrings |
Solution |
| 697 |
Degree of an Array |
Solution |
| 700 |
Search in a Binary Search Tree |
Solution |
| 702 |
Search in a Sorted Array of Unknown Size |
Solution |
| 703 |
Kth Largest Element in a Stream |
Solution |
| 704 |
Binary Search |
Solution |
| 706 |
Design HashMap |
Solution |
| 713 |
Subarray Product Less Than K |
Solution |
| 739 |
Daily Temperatures |
Solution |
| 767 |
Reorganize String |
Solution |
| 796 |
Rotate String |
Solution |
| 845 |
Longest Mountain in Array |
Solution |
| 875 |
Koko Eating Bananas |
Solution |
| 876 |
Middle of the Linked List |
Solution |
| 889 |
Construct Binary Tree from Preorder and Postorder Traversal |
Solution |
| 912 |
Sort an Array |
Solution |
| 953 |
Verifying an Alien Dictionary |
Solution |
| 973 |
K Closest Points to Origin |
Solution |
| 986 |
Interval List Intersections |
Solution |
| 1019 |
Next Greater Node In Linked List |
Solution |
| 1021 |
Remove Outermost Parentheses |
Solution |
| 1032 |
Stream of Characters |
Solution |
| 1047 |
Remove All Adjacent Duplicates In String |
Solution |