| 1 |
Two Sum |
Easy ✔️ |
| 7 |
Reverse Integer |
Easy ✔️ |
| 13 |
Roman to Integer |
Easy ✔️ |
| 704 |
Binary Search |
Easy ✔️ |
| 35 |
Search Insert Position |
Easy ✔️ |
| 557 |
Reverse Words in a String III |
Easy ✔️ |
| 344 |
Reverse String |
Easy ✔️ |
| 733 |
Flood Fill |
Easy ✔️ |
| 977 |
Squares of sorted array |
Easy ✔️ |
| 283 |
Move zeros |
Easy ✔️ |
| 876 |
Middle of the Linked List |
Easy ✔️ |
| 680 |
Valid Palindrome II |
Easy ✔️ |
| 125 |
Valid Palindrome |
Easy ✔️ |
| 617 |
Merge Two Binary Trees |
Easy ✔️ |
| 206 |
Reverse Linked List |
Easy ✔️ |
| 703 |
Kth Largest Element in a Stream |
Easy ✔️ |
| 700 |
Search in a Binary Search Tree |
Easy ✔️ |
| 217 |
Contains Duplicate |
Easy ✔️ |
| 242 |
Valid Anagram |
Easy ✔️ |
| 108 |
Convert Sorted Array to Binary Search Tree |
Easy ✔️ |
| 121 |
Best Time to Buy and Sell Stock |
Easy ✔️ |
| 94 |
Binary Tree Inorder Traversal |
Easy ✔️ |
| 104 |
Maximum Depth of Binary Tree |
Easy ✔️ |
| 1379 |
Find a Corresponding Node of a Binary Tree in a Clone of That Tree |
Easy ✔️ |
| 226 |
Invert Binary Tree |
Easy ✔️ |
| 100 |
Same Tree |
Easy ✔️ |
| 387 |
First Unique Character in a String |
Easy ✔️ |
| 2351 |
First Letter to Appear Twice |
Easy ✔️ |
| 804 |
Unique Morse Code Words |
Easy ✔️ |
| 342 |
Power of Four |
Easy ✔️ |
| 234 |
Palindrome Linked List |
Easy ✔️ |
| 326 |
Power of Three |
Easy ✔️ |
| 383 |
Ransom Note |
Easy ✔️ |
| 637 |
Average of Levels in Binary Tree |
Easy ✔️ |
| 404 |
Sum of Left Leaves |
Easy ✔️ |
| 111 |
Minimum Depth of Binary Tree |
Easy ✔️ |
| 1929 |
Concatenation of Array |
Easy ✔️ |
| 26 |
Remove Duplicates from Sorted Array |
Easy ✔️ |
| 27 |
Remove Element |
Easy ✔️ |
| 203 |
Remove Linked List Elements |
Easy ✔️ |
| 645 |
Set Mismatch |
Easy ✔️ |
| 682 |
Baseball Game |
Easy ✔️ |
| 20 |
Valid Parentheses |
Easy ✔️ |
| 232 |
Implement Queue using Stacks |
Easy ✔️ |
| 225 |
Implement Stack using Queues |
Easy ✔️ |
| 933 |
Number of Recent Calls |
Easy ✔️ |
| 21 |
Merge Two Sorted Lists |
Easy ✔️ |
| 141 |
Linked List Cycle |
Easy ✔️ |
| 160 |
Intersection of Two Linked Lists |
Easy ✔️ |
| 1470 |
Shuffle the Array |
Easy ✔️ |
| 744 |
Find Smallest Letter Greater Than Target |
Easy ✔️ |
| 1700 |
Number of Students Unable to Eat Lunch |
Easy ✔️ |
| 225 |
Implement Stack using Queues |
Easy ✔️ |
| 374 |
Guess Number Higher or Lower |
Easy ✔️ |
| 2095 |
Delete the Middle Node of a Linked List |
Medium ✔️ |
| 695 |
Max Area of Island |
Medium ✔️ |
| 200 |
Number of Islands |
Medium ✔️ |
| 189 |
Rotate Array |
Medium ✔️ |
| 215 |
Kth Largest Element in an Array |
Medium ✔️ |
| 347 |
Top K Frequent Elements |
Medium ✔️ |
| 669 |
Trim a Binary Search Tree |
Medium ✔️ |
| 538 |
Convert BST to Greater Tree |
Medium ✔️ |
| 128 |
Longest Consecutive Sequence |
Medium ✔️ |
| 49 |
Group Anagrams |
Medium ✔️ |
| 238 |
Product of Array Except Self |
Medium ✔️ |
| 34 |
Find First and Last Position of Element in Sorted Array |
Medium ✔️ |
| 102 |
Binary Tree Level Order Traversal |
Medium ✔️ |
| 107 |
Binary Tree Level Order Traversal II |
Medium ✔️ |
| 1338 |
Reduce Array Size to The Half |
Medium ✔️ |
| 451 |
Sort Characters By Frequency |
Medium ✔️ |
| 2 |
Add Two Numbers |
Medium ✔️ |
| 3 |
Longest Substring Without Repeating Characters |
Medium ✔️ |
| 1448 |
Count Good Nodes in Binary Tree |
Medium ✔️ |
| 429 |
N-ary Tree Level Order Traversal |
Medium ✔️ |
| 155 |
Min Stack |
Medium ✔️ |
| 142 |
Linked List Cycle II |
Medium ✔️ |
| 287 |
Find the Duplicate Number |
Medium ✔️ |
| 143 |
Reorder List |
Medium ✔️ |
| 707 |
Design Linked List |
Medium ✔️ |
| 1472 |
Design Browser History |
Medium ✔️ |
| 912 |
Sort an Array |
Medium ✔️ |
| 75 |
Sort Colors |
Medium ✔️ |
| 74 |
Search a 2D Matrix |
Medium ✔️ |
| 875 |
Koko Eating Bananas |
Medium ✔️ |
| 701 |
Insert into a Binary Search Tree |
Medium ✔️ |
| 450 |
Delete Node in a BST |
Medium ✔️ |
| 199 |
Binary Tree Right Side View |
Medium ✔️ |
| 23 |
Merge k Sorted Lists |
Hard ✔️ |