| 1 |
Two Sum |
Java |
|
Easy |
| 2 |
Add Two Numbers |
Java |
|
Medium |
| 3 |
Longest Substring Without Repeating Characters |
Java |
|
Medium |
| 5 |
Longest Palindromic Substring |
Java |
|
Medium |
| 7 |
Reverse Integer |
Java |
|
Easy |
| 8 |
String to Integer (atoi) |
Java |
|
Medium |
| 9 |
Palindrome Number |
Java |
|
Easy |
| 11 |
Container With Most Water |
Java |
|
Medium |
| 13 |
Roman to Integer |
Java |
|
Easy |
| 14 |
Longest Common Prefix |
Java |
|
Easy |
| 15 |
3Sum |
Java |
|
Medium |
| 16 |
3Sum Closest |
Java |
|
Medium |
| 17 |
Letter Combinations of a Phone Number |
Java |
|
Medium |
| 18 |
4Sum |
Java |
|
Medium |
| 19 |
Remove Nth Node From End of List |
Java |
|
Medium |
| 20 |
Valid Parentheses |
Java |
|
Easy |
| 21 |
Merge Two Sorted Lists |
Java |
|
Easy |
| 22 |
Generate Parentheses |
Java |
|
Medium |
| 24 |
Swap Nodes in Pairs |
Java |
|
Medium |
| 26 |
Remove Duplicates from Sorted Array |
Java |
|
Easy |
| 27 |
Remove Element |
Java |
|
Easy |
| 28 |
Implement strStr() |
Java |
|
Easy |
| 31 |
Next Permutation |
Java |
|
Medium |
| 33 |
Search in Rotated Sorted Array |
Java |
|
Medium |
| 34 |
Find First and Last Position of Element in Sorted Array |
Java |
|
Medium |
| 35 |
Search Insert Position |
Java |
|
Easy |
| 36 |
Valid Sudoku |
Java |
|
Medium |
| 38 |
Count and Say |
Java |
|
Easy |
| 39 |
Combination Sum |
Java |
|
Medium |
| 40 |
Combination Sum II |
Java |
|
Medium |
| 46 |
Permutations |
Java |
|
Medium |
| 47 |
Permutations II |
Java |
|
Medium |
| 48 |
Rotate Image |
Java |
|
Medium |
| 49 |
Group Anagrams |
Java |
|
Medium |
| 50 |
Pow(x, n) |
Java |
|
Medium |
| 53 |
Maximum Subarray |
Java |
|
Easy |
| 54 |
Spiral Matrix |
Java |
|
Medium |
| 55 |
Jump Game |
Java |
|
Medium |
| 56 |
Merge Intervals |
Java |
|
Medium |
| 57 |
Insert Interval |
Java |
|
Hard |
| 58 |
Length of Last Word |
Java |
|
Easy |
| 59 |
Spiral Matrix II |
Java |
|
Medium |
| 60 |
Permutation Sequence |
Java |
|
Medium |
| 61 |
Rotate List |
Java |
|
Medium |
| 62 |
Unique Paths |
Java |
|
Medium |
| 63 |
Unique Paths II |
Java |
|
Medium |
| 64 |
Minimum Path Sum |
Java |
|
Medium |
| 66 |
Plus One |
Java |
|
Easy |
| 67 |
Add Binary |
Java |
|
Easy |
| 69 |
Sqrt(x) |
Java |
|
Easy |
| 70 |
Climbing Stairs |
Java |
|
Easy |
| 73 |
Set Matrix Zeroes |
Java |
|
Medium |
| 74 |
Search a 2D Matrix |
Java |
|
Medium |
| 75 |
Sort Colors |
Java |
|
Medium |
| 77 |
Combinations |
Java |
|
Medium |
| 78 |
Subsets |
Java |
|
Medium |
| 79 |
Word Search |
Java |
|
Medium |
| 80 |
Remove Duplicates from Sorted Array II |
Java |
|
Medium |
| 81 |
Search in Rotated Sorted Array II |
Java |
|
Medium |
| 82 |
Remove Duplicates from Sorted List II |
Java |
|
Medium |
| 83 |
Remove Duplicates from Sorted List |
Java |
|
Easy |
| 84 |
Largest Rectangle in Histogram |
Java |
|
Hard |
| 86 |
Partition List |
Java |
|
Medium |
| 88 |
Merge Sorted Array |
Java |
|
Easy |
| 90 |
Subsets II |
Java |
|
Medium |
| 92 |
Reverse Linked List II |
Java |
|
Medium |
| 93 |
Restore IP Addresses |
Java |
|
Medium |
| 94 |
Binary Tree Inorder Traversal |
Java |
|
Medium |
| 95 |
Unique Binary Search Trees II |
Java |
|
Medium |
| 96 |
Unique Binary Search Trees |
Java |
|
Medium |
| 98 |
Validate Binary Search Tree |
Java |
|
Medium |
| 100 |
Same Tree |
Java |
|
Easy |
| 101 |
Symmetric Tree |
Java |
|
Easy |
| 102 |
Binary Tree Level Order Traversal |
Java |
|
Medium |
| 103 |
Binary Tree Zigzag Level Order Traversal |
Java |
|
Medium |
| 104 |
Maximum Depth of Binary Tree |
Java |
|
Easy |
| 105 |
Construct Binary Tree from Preorder and Inorder Traversal |
Java |
|
Medium |
| 106 |
Construct Binary Tree from Inorder and Postorder Traversal |
Java |
|
Medium |
| 107 |
Binary Tree Level Order Traversal II |
Java |
|
Easy |
| 108 |
Convert Sorted Array to Binary Search Tree |
Java |
|
Easy |
| 109 |
Convert Sorted List to Binary Search Tree |
Java |
|
Medium |
| 110 |
Balanced Binary Tree |
Java |
|
Easy |
| 111 |
Minimum Depth of Binary Tree |
Java |
|
Easy |
| 112 |
Path Sum |
Java |
|
Easy |
| 113 |
Path Sum II |
Java |
|
Medium |
| 114 |
Flatten Binary Tree to Linked List |
Java |
|
Medium |
| 116 |
Populating Next Right Pointers in Each Node |
Java |
|
Medium |
| 118 |
Pascal's Triangle |
Java |
|
Easy |
| 119 |
Pascal's Triangle II |
Java |
|
Easy |
| 120 |
Triangle |
Java |
|
Medium |
| 121 |
Best Time to Buy and Sell Stock |
Java |
|
Easy |
| 122 |
Best Time to Buy and Sell Stock II |
Java |
|
Easy |
| 125 |
Valid Palindrome |
Java |
|
Easy |
| 130 |
Surrounded Regions |
Java |
|
Medium |
| 131 |
Palindrome Partitioning |
Java |
|
Medium |
| 134 |
Gas Station |
Java |
|
Medium |
| 136 |
Single Number |
Java |
|
Easy |
| 138 |
Copy List with Random Pointer |
Java |
|
Medium |
| 139 |
Word Break |
Java |
|
Medium |
| 141 |
Linked List Cycle |
Java |
|
Easy |
| 142 |
Linked List Cycle II |
Java |
|
Medium |
| 144 |
Binary Tree Preorder Traversal |
Java |
|
Medium |
| 147 |
Insertion Sort List |
Java |
|
Medium |
| 148 |
Sort List |
Java |
|
Medium |
| 150 |
Evaluate Reverse Polish Notation |
Java |
|
Medium |
| 152 |
Maximum Product Subarray |
Java |
|
Medium |
| 153 |
Find Minimum in Rotated Sorted Array |
Java |
|
Medium |
| 155 |
Min Stack |
Java |
|
Easy |
| 160 |
Intersection of Two Linked Lists |
Java |
|
Easy |
| 162 |
Find Peak Element |
Java |
|
Medium |
| 167 |
Two Sum II - Input array is sorted |
Java |
|
Easy |
| 169 |
Majority Element |
Java |
|
Easy |
| 171 |
Excel Sheet Column Number |
Java |
|
Easy |
| 172 |
Factorial Trailing Zeroes |
Java |
|
Easy |
| 187 |
Repeated DNA Sequences |
Java |
|
Medium |
| 189 |
Rotate Array |
Java |
|
Easy |
| 190 |
Reverse Bits |
Java |
|
Easy |
| 191 |
Number of 1 Bits |
Java |
|
Easy |
| 198 |
House Robber |
Java |
|
Easy |
| 199 |
Binary Tree Right Side View |
Java |
|
Medium |
| 200 |
Number of Islands |
Java |
|
Medium |
| 202 |
Happy Number |
Java |
|
Easy |
| 204 |
Count Primes |
Java |
|
Easy |
| 205 |
Isomorphic Strings |
Java |
|
Easy |
| 206 |
Reverse Linked List |
Java |
|
Easy |
| 207 |
Course Schedule |
Java |
|
Medium |
| 209 |
Minimum Size Subarray Sum |
Java |
|
Medium |
| 213 |
House Robber II |
Java |
|
Medium |
| 215 |
Kth Largest Element in an Array |
Java |
|
Medium |
| 216 |
Combination Sum III |
Java |
|
Medium |
| 217 |
Contains Duplicate |
Java |
|
Easy |
| 219 |
Contains Duplicate II |
Java |
|
Easy |
| 220 |
Contains Duplicate III |
Java |
|
Medium |
| 221 |
Maximal Square |
Java |
|
Medium |
| 226 |
Invert Binary Tree |
Java |
|
Easy |
| 230 |
Kth Smallest Element in a BST |
Java |
|
Medium |
| 234 |
Palindrome Linked List |
Java |
|
Easy |
| 235 |
Lowest Common Ancestor of a Binary Search Tree |
Java |
|
Easy |
| 236 |
Lowest Common Ancestor of a Binary Tree |
Java |
|
Medium |
| 237 |
Delete Node in a Linked List |
Java |
|
Easy |
| 238 |
Product of Array Except Self |
Java |
|
Medium |
| 240 |
Search a 2D Matrix II |
Java |
|
Medium |
| 242 |
Valid Anagram |
Java |
|
Easy |
| 257 |
Binary Tree Paths |
Java |
|
Easy |
| 258 |
Add Digits |
Java |
|
Easy |
| 263 |
Ugly Number |
Java |
|
Easy |
| 264 |
Ugly Number II |
Java |
|
Medium |
| 268 |
Missing Number |
Java |
|
Easy |
| 274 |
H-Index |
Java |
|
Medium |
| 275 |
H-Index II |
Java |
|
Medium |
| 279 |
Perfect Squares |
Java |
|
Medium |
| 283 |
Move Zeroes |
Java |
|
Easy |
| 287 |
Find the Duplicate Number |
Java |
|
Medium |
| 290 |
Word Pattern |
Java |
|
Easy |
| 299 |
Bulls and Cows |
Java |
|
Medium |
| 300 |
Longest Increasing Subsequence |
Java |
|
Medium |
| 303 |
Range Sum Query - Immutable |
Java |
|
Easy |
| 304 |
Range Sum Query 2D - Immutable |
Java |
|
Medium |
| 309 |
Best Time to Buy and Sell Stock with Cooldown |
Java |
|
Medium |
| 322 |
Coin Change |
Java |
|
Medium |
| 324 |
Wiggle Sort II |
Java |
|
Medium |
| 326 |
Power of Three |
Java |
|
Easy |
| 328 |
Odd Even Linked List |
Java |
|
Medium |
| 334 |
Increasing Triplet Subsequence |
Java |
|
Medium |
| 337 |
House Robber III |
Java |
|
Medium |
| 338 |
Counting Bits |
Java |
|
Medium |
| 341 |
Flatten Nested List Iterator |
Java |
|
Medium |
| 344 |
Reverse String |
Java |
|
Easy |
| 345 |
Reverse Vowels of a String |
Java |
|
Easy |
| 347 |
Top K Frequent Elements |
Java |
|
Medium |
| 349 |
Intersection of Two Arrays |
Java |
|
Easy |
| 350 |
Intersection of Two Arrays II |
Java |
|
Easy |
| 371 |
Sum of Two Integers |
Java |
|
Easy |
| 378 |
Kth Smallest Element in a Sorted Matrix |
Java |
|
Medium |
| 380 |
Insert Delete GetRandom O(1) |
Java |
|
Medium |
| 383 |
Ransom Note |
Java |
|
Easy |
| 387 |
First Unique Character in a String |
Java |
|
Easy |
| 389 |
Find the Difference |
Java |
|
Easy |
| 392 |
Is Subsequence |
Java |
|
Medium |
| 394 |
Decode String |
Java |
|
Medium |
| 404 |
Sum of Left Leaves |
Java |
|
Easy |
| 406 |
Queue Reconstruction by Height |
Java |
|
Medium |
| 409 |
Longest Palindrome |
Java |
|
Easy |
| 412 |
Fizz Buzz |
Java |
|
Easy |
| 414 |
Third Maximum Number |
Java |
|
Easy |
| 416 |
Partition Equal Subset Sum |
Java |
|
Medium |
| 434 |
Number of Segments in a String |
Java |
|
Easy |
| 435 |
Non-overlapping Intervals |
Java |
|
Medium |
| 437 |
Path Sum III |
Java |
|
Easy |
| 448 |
Find All Numbers Disappeared in an Array |
Java |
|
Easy |
| 452 |
Minimum Number of Arrows to Burst Balloons |
Java |
|
Medium |
| 455 |
Assign Cookies |
Java |
|
Easy |
| 459 |
Repeated Substring Pattern |
Java |
|
Easy |
| 463 |
Island Perimeter |
Java |
|
Easy |
| 485 |
Max Consecutive Ones |
Java |
|
Easy |
| 494 |
Target Sum |
Java |
|
Medium |
| 501 |
Find Mode in Binary Search Tree |
Java |
|
Easy |
| 520 |
Detect Capital |
Java |
|
Easy |
| 521 |
Longest Uncommon Subsequence I |
Java |
|
Easy |
| 524 |
Longest Word in Dictionary through Deleting |
Java |
|
Medium |
| 530 |
Minimum Absolute Difference in BST |
Java |
|
Easy |
| 532 |
K-diff Pairs in an Array |
Java |
|
Easy |
| 541 |
Reverse String II |
Java |
|
Easy |
| 551 |
Student Attendance Record I |
Java |
|
Easy |
| 557 |
Reverse Words in a String III |
Java |
|
Easy |
| 560 |
Subarray Sum Equals K |
Java |
|
Medium |
| 561 |
Array Partition I |
Java |
|
Easy |
| 566 |
Reshape the Matrix |
Java |
|
Easy |
| 581 |
Shortest Unsorted Continuous Subarray |
Java |
|
Easy |
| 605 |
Can Place Flowers |
Java |
|
Easy |
| 606 |
Construct String from Binary Tree |
Java |
|
Easy |
| 621 |
Task Scheduler |
Java |
|
Medium |
| 628 |
Maximum Product of Three Numbers |
Java |
|
Easy |
| 643 |
Maximum Average Subarray I |
Java |
|
Easy |
| 647 |
Palindromic Substrings |
Java |
|
Medium |
| 657 |
Robot Return to Origin |
Java |
|
Easy |
| 661 |
Image Smoother |
Java |
|
Easy |
| 665 |
Non-decreasing Array |
Java |
|
Easy |
| 674 |
Longest Continuous Increasing Subsequence |
Java |
|
Easy |
| 680 |
Valid Palindrome II |
Java |
|
Easy |
| 686 |
Repeated String Match |
Java |
|
Easy |
| 687 |
Longest Univalue Path |
Java |
|
Easy |
| 690 |
Employee Importance |
Java |
|
Easy |
| 695 |
Max Area of Island |
Java |
|
Medium |
| 698 |
Partition to K Equal Sum Subsets |
Java |
|
Medium |
| 733 |
Flood Fill |
Java |
|
Easy |
| 744 |
Network Delay Time |
Java |
|
Easy |
| 747 |
Min Cost Climbing Stairs |
Java |
|
Easy |
| 764 |
N-ary Tree Level Order Traversal |
Java |
|
Easy |
| 774 |
Maximum Depth of N-ary Tree |
Java |
|
Easy |
| 799 |
Minimum Distance Between BST Nodes |
Java |
|
Easy |
| 874 |
Backspace String Compare |
Java |
|
Easy |
| 879 |
Maximize Distance to Closest Person |
Java |
|
Easy |
| 890 |
Lemonade Change |
Java |
|
Easy |
| 898 |
Transpose Matrix |
Java |
|
Easy |
| 904 |
Leaf-Similar Trees |
Java |
|
Easy |
| 908 |
Middle of the Linked List |
Java |
|
Easy |
| 920 |
Uncommon Words from Two Sentences |
Java |
|
Easy |
| 924 |
Fair Candy Swap |
Java |
|
Easy |
| 932 |
Monotonic Array |
Java |
|
Easy |
| 941 |
Sort Array By Parity |
Java |
|
Easy |
| 950 |
X of a Kind in a Deck of Cards |
Java |
|
Easy |