1️⃣ Sorting & Searching Problems
- Search Insert Position – Easy
- Sort Colors – Medium
- Top K Frequent Elements – Medium
- Top K Frequent Words – Medium
- Sort Characters By Frequency – Medium
- Merge Intervals – Medium
- Find Peak Element – Medium
- H-Index – Medium
2️⃣ Array & Matrix Problems
- Two Sum – Easy
- Move Zeroes – Easy
- Remove Duplicates from Sorted Array – Easy
- Best Time to Buy and Sell Stock II – Easy
- Jewels and Stones – Easy
- Longest Common Prefix – Easy
- Valid Tic-Tac-Toe State – Medium
- Count Primes – Medium
- Maximum Subarray – Medium
- Next Greater Element II – Medium
- Product of Array Except Self – Medium
- Triangle – Medium
- Partition Equal Subset Sum – Medium
- Number of Islands – Medium
- Daily Temperatures – Medium
- 3Sum – Medium
3️⃣ Linked List Problems
- Merge Two Sorted Lists – Easy
- Intersection of Two Linked Lists – Easy
- Linked List Cycle – Easy
- Remove Linked List Elements – Easy
- Reverse Linked List – Easy
- Add Two Numbers – Medium
- Partition List – Medium
- Swap Nodes in Pairs – Medium
- Reverse Linked List II – Medium
- Convert Sorted List to Binary Search Tree – Medium
- Copy List with Random Pointer – Medium
- Delete Node in a Linked List – Easy
4️⃣ String Problems
- Valid Anagram – Easy
- Palindrome Number – Easy
- Excel Sheet Column Title – Easy
- First Unique Character in a String – Easy
- Valid Palindrome II – Easy
- Isomorphic Strings – Easy
- Reverse Integer – Easy
- Generate Parentheses – Medium
- Group Anagrams – Medium
- Decode String – Medium
- Letter Combinations of a Phone Number – Medium
- Longest Substring Without Repeating Characters – Medium
- Decode Ways – Medium
- Integer to Roman – Medium
- Integer to English Words – Hard
- Longest Palindromic Substring – Medium
5️⃣ Tree & Graph Problems
- Maximum Depth of Binary Tree – Easy
- Convert Sorted Array to Binary Search Tree – Easy
- Path Sum – Easy
- Binary Tree Level Order Traversal – Medium
- Binary Tree Zigzag Level Order Traversal – Medium
- Count Complete Tree Nodes – Medium
- Unique Binary Search Trees II – Medium
- Verify Preorder Serialization of a Binary Tree – Medium
- Lowest Common Ancestor of a Binary Tree – Medium
- House Robber III – Medium
- All Paths From Source to Target – Medium
- Alien Dictionary – Hard
- Serialize and Deserialize Binary Tree – Hard
6️⃣ Dynamic Programming Problems
- Climbing Stairs – Easy
- Permutations – Medium
- Subsets – Medium
- Coin Change 2 – Medium
- Word Search – Medium
- Permutation in String – Medium
- Edit Distance – Hard
- Longest Increasing Subsequence – Medium
7️⃣ Stack & Queue Problems
- Implement Stack using Queues – Easy
- Design Hit Counter – Medium
- Daily Temperatures – Medium
8️⃣ Miscellaneous Problems
- LRU Cache – Hard
- Single Number III – Medium
- Find Median from Data Stream – Hard
- Employees Earning More Than Their Managers – Easy
- Second Highest Salary – Easy
- Combine Two Tables – Easy