- Search in Rotated Sorted Array - Binary Search
- Find First and Last Position of Element in Sorted Array
- Search in Rotated Sorted Array II
- Search a 2D Matrix
- Longest Common Prefix
- Sum of Two Integers - Mask
- Same Tree
- Find the Index of the First Occurrence in a String
- Two Sum- HashTable
- Add Two Numbers - Linked List
- Valid Parentheses
- Implement Queue using Stacks
- First Unique Character in a String
- Number of Recent Calls
- Implement Stack using Queues
- Longest Substring Without Repeating Characters
- Average contiguous K elements
- Smallest contiguous subarray
- Longest Substring with K Distinct Characters
- Fruit Into Baskets
- Longest Repeating Character Replacement
- Max Consecutive Ones III
- Permutation in String
- Contains Duplicate II