| 1 |
two sum |
link |
easy |
| 2 |
add two numbers |
link |
medium |
| 3 |
Longest Substring Without Repeating |
link |
medium |
| 4 |
Median of Two Sorted Arrays |
link |
hard |
| 5 |
LLongest Palindromic Substring |
link |
medium |
| 6 |
ZigZag Conversion |
link |
medium |
| 7 |
Reverse Integer |
link |
easy |
| 8 |
String to Integer |
link |
medium |
| 9 |
Palindrome Number |
link |
easy |
| 10 |
Regular Expression Matching |
link |
hard |
| 11 |
container with most water |
link |
medium |
| 12 |
Integer to Roman |
link |
medium |
| 13 |
Roman to Integer |
link |
easy |
| 14 |
Longest Common Prefix |
link |
easy |
| 15 |
3 Sum |
link |
medium |
| 16 |
3Sum Closest |
link |
medium |
| 17 |
Letter Combinations of a Phone Number |
link |
medium |
| 18 |
4 sum |
link |
medium |
| 19 |
Remove Nth Node From End of List |
link |
medium |
| 20 |
Valid Parentheses |
link |
easy |
| 21 |
Merge Two Sorted Lists |
link |
easy |
| 22 |
Generate Parentheses |
link |
medium |
| 23 |
Merge k Sorted Lists |
link |
hard |
| 24 |
Swap Nodes in Pairs |
link |
medium |
| 25 |
Reverse Nodes in k-Group |
link |
hard |
| 26 |
Remove Duplicates from Sorted Array |
link |
easy |
| 27 |
Remove Element |
link |
easy |
| 28 |
Implement strStr |
link |
easy |
| 29 |
Divide Two Integers |
link |
medium |
| 30 |
Substring with Concatenation of All Words |
link |
Hard |
| 31 |
Next Permutation |
link |
medium |
| 32 |
Longest Valid Parentheses |
link |
hard |
| 33 |
Search in Rotated Sorted Array |
link |
medium |
| 34 |
Find First and Last Position of Element in Sorted Array |
link |
Medium |
| 35 |
Search Insert Position |
link |
Easy |
| 36 |
Valid Sudoku |
link |
Medium |
| 37 |
Sudoku Solver |
link |
Hard |
| 39 |
Combination Sum |
link |
Medium |
| 40 |
Combination Sum II |
link |
Medium |
| 41 |
First Missing Positive |
link |
Hard |
| 42 |
Trapping Rain Water |
link |
Hard |
| 43 |
Multiply Strings |
link |
medium |
| 44 |
Wildcard Matching |
link |
Hard |
| 45 |
Jump Game II |
link |
Hard |
| 46 |
Permutations |
link |
medium |
| 47 |
Permutations II |
link |
Medium |
| 48 |
Rotate Image |
link |
medium |
| 49 |
Group Anagrams |
link |
Medium |
| 50 |
Pow(x, n) |
link |
Medium |
| 53 |
Maximum Subarray |
link |
Easy |
| 54 |
Spiral Matrix |
link |
medium |
| 55 |
Jump Game |
link |
Medium |
| 56 |
Merge Intervals |
link |
Medium |
| 57 |
Insert Interval |
link |
Hard |
| 59 |
Spiral Matrix II |
link |
Medium |
| 61 |
Rotate List |
link |
Medium |
| 62 |
Unique Paths |
link |
medium |
| 63 |
Unique Paths II |
link |
Medium |
| 64 |
Minimum Path Sum |
link |
Medium |
| 70 |
Climbing Stairs |
link |
easy |
| 71 |
Simplify Path |
link |
Medium |
| 72 |
Edit Distance |
link |
Hard |
| 75 |
Sort Colors |
link |
Medium |
| 76 |
Minimum Window Substring |
link |
Hard |
| 77 |
Combinations |
link |
Medium |
| 78 |
Subsets |
link |
medium |
| 79 |
Word Search |
link |
Medium |
| 80 |
Remove Duplicates from Sorted Array II |
link |
Medium |
| 82 |
Remove Duplicates from Sorted List II |
link |
Medium |
| 84 |
Largest Rectangle in Histogram |
link |
hard |
| 85 |
Maximal Rectangle |
link |
hard |
| 88 |
Merge Sorted Array |
link |
Easy |
| 89 |
Gray Code |
link |
medium |
| 91 |
Decode Ways |
link |
Medium |
| 92 |
Reverse Linked List II |
link |
Medium |
| 94 |
Binary Tree Inorder Traversal |
link |
Medium |
| 95 |
Unique Binary Search Trees II |
link |
Medium |
| 96 |
Unique Binary Search Trees |
link |
Medium |
| 97 |
Interleaving String |
link |
Hard |
| 98 |
Validate Binary Search Tree |
link |
Medium |
| 99 |
Recover Binary Search Tree |
link |
Hard |
| 100 |
Same Tree |
link |
Easy |
| 101 |
Symmetric Tree |
link |
Easy |
| 102 |
Binary Tree Level Order Traversal |
link |
Medium |
| 103 |
Binary Tree Zigzag Level Order Traversal |
link |
Medium |
| 104 |
Maximum Depth of Binary Tree |
link |
easy |
| 108 |
Convert Sorted Array to Binary Search Tree |
link |
easy |
| 112 |
Path Sum |
link |
Easy |
| 121 |
Best Time to Buy and Sell Stock |
link |
Easy |
| 122 |
Best Time to Buy and Sell Stock II |
link |
easy |
| 123 |
Best Time to Buy and Sell Stock III |
link |
hard |
| 124 |
Binary Tree Maximum Path Sum |
link |
hard |
| 136 |
Single Number |
link |
easy |
| 141 |
Linked List Cycle |
link |
easy |
| 142 |
Linked List Cycle II |
link |
medium |
| 144 |
Binary Tree Preorder Traversal |
link |
Medium |
| 145 |
Binary Tree Postorder Traversal |
link |
Hard |
| 146 |
LRU Cache |
link |
hard |
| 147 |
Insertion Sort List |
link |
Medium |
| 148 |
Sort List |
link |
medium |
| 155 |
Min Stack |
link |
easy |
| 160 |
Intersection of Two Linked Lists |
link |
easy |
| 169 |
Majority Element |
link |
easy |
| 173 |
Binary Search Tree Iterator |
link |
Medium |
| 174 |
Dungeon Game |
link |
Hard |
| 179 |
Largest Number |
link |
medium |
| 188 |
Best Time to Buy and Sell Stock IV |
link |
hard |
| 189 |
Rotate Array |
link |
Easy |
| 199 |
Binary Tree Right Side View |
link |
Medium |
| 206 |
Reverse Linked List |
link |
easy |
| 213 |
House Robber II |
link |
Medium |
| 214 |
Shortest Palindrome |
link |
Hard |
| 215 |
Kth Largest Element in an Array |
link |
medium |
| 217 |
Contains Duplicate |
link |
Easy |
| 224 |
Basic Calculator |
link |
hard |
| 227 |
Basic Calculator II |
link |
medium |
| 230 |
Kth Smallest Element in a BST |
link |
medium |
| 231 |
Power of Two |
link |
easy |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
link |
easy |
| 236 |
Lowest Common Ancestor of a Binary Tree |
link |
medium |
| 237 |
Delete Node in a Linked List |
link |
easy |
| 238 |
Product of Array Except Self |
link |
easy |
| 239 |
Sliding Window Maximum |
link |
hard |
| 240 |
Search a 2D Matrix II |
link |
Medium |
| 279 |
Perfect Squares |
link |
Medium |
| 287 |
Find the Duplicate Number |
link |
Medium |
| 292 |
Nim Game |
link |
easy |
| 295 |
Find Median from Data Stream |
link |
hard |
| 300 |
Longest Increasing Subsequence |
link |
Medium |
| 309 |
Best Time to Buy and Sell Stock with Cooldown |
link |
medium |
| 312 |
Burst Balloons |
link |
Hard |
| 321 |
Create Maximum Number |
link |
Hard |
| 322 |
Coin Change |
link |
Medium |
| 329 |
Longest Increasing Path in a Matrix |
link |
hard |
| 341 |
Flatten Nested List Iterator |
link |
medium |
| 344 |
Reverse String |
link |
easy |
| 347 |
Top K Frequent Elements |
link |
Medium |
| 386 |
Lexicographical Numbers |
link |
medium |
| 393 |
UTF-8 Validation |
link |
medium |
| 416 |
Partition Equal Subset Sum |
link |
Medium |
| 455 |
Assign Cookies |
link |
Easy |
| 456 |
132 Pattern |
link |
medium |
| 473 |
Matchsticks to Square |
link |
Medium |
| 496 |
Next Greater Element I |
link |
Easy |
| 518 |
Coin Change 2 |
link |
Medium |
| 557 |
Reverse Words in a String III |
link |
easy |
| 611 |
Valid Triangle Number |
link |
medium |
| 628 |
Maximum Product of Three Numbers |
link |
Easy |
| 632 |
Smallest Range |
link |
Hard |
| 645 |
Set Mismatch |
link |
Easy |
| 687 |
Longest Univalue Path |
link |
Easy |
| 698 |
Partition to K Equal Sum Subsets |
link |
Medium |
| 704 |
Binary Search |
link |
easy |
| 726 |
Number of Atoms |
link |
Hard |
| 729 |
My Calendar I |
link |
medium |
| 731 |
My Calendar II |
link |
medium |
| 732 |
My Calendar III |
link |
hard |
| 739 |
Daily Temperatures |
link |
Medium |
| 779 |
K-th Symbol in Grammar |
link |
Medium |
| 794 |
Valid Tic-Tac-Toe State |
link |
Medium |
| 828 |
Unique Letter String |
link |
Hard |
| 838 |
Push Dominoes |
link |
Medium |
| 881 |
Boats to Save People |
link |
Medium |
| 887 |
Super Egg Drop |
link |
hard |
| 894 |
All Possible Full Binary Trees |
link |
Medium |
| 994 |
Rotting Oranges |
link |
easy |