Surrounded Regions
Two Sum
Valid Parentheses
Merge two sorted lists
Best time to Buy & Sell stock
Valid Palindrome
Invert Binary Tree
Valid Anagram
Binary Search
Flood Fill
Maximum Subarray
Lowest common ancestor of a binary search tree
Balanced Binary tree
Linked List Cycle
Implement Queue Using Stacks
First Bad Version
Ransom Note
Climbing Stairs
Longest Palindrome
Reverse Linked List
Majority Element
Add Binary
Diameter of Binary Tree
Middle of the Linked List
Maximum Depth of Binary Tree
Contains Duplicate
Meeting rooms
Roman to Integer
Backspace string compare
Counting Bits
Same Tree
Number of 1 Bits
Longest Common Prefix
Single Number
Palindrome Linked List
Move Zeroes
Symmetric Tree
Missing Number
Palindrome Number
Convert Sorted Array to Binary Search Tree
Reverse Bits
Subtree of Another Tree
Squares of a Sorted Array
Insert Interval
01 Matrix
K Closest Points to Origin
Longest Substring Without Repeating Characters
3 Sum
Binary Tree Level Order Traversal
Clone Graph
Evaluate Reverse Polish Notation
Course Schedule
Implement Trie (Prefix Tree)
Coin Change
Product of Array Except Self
Min Stack
Validate Binary Search Tree
Number of Islands
Rotting Oranges
Search in Rotated Sorted Array
Combination Sum
Permutations
Merge Intervals
Lowest common ancestor of a binary tree
Time Based Key Value Store
Accounts Merge
Sort Colors
Word Break
Partition Equal Subset Sum
String to Integer (atoi)
Spiral Matrix
Subsets
Binary Tree Right Side View
Longest Palindromic Substring
Unique Paths
Construct Binary Tree from Preorder and Inorder Traversal
Container With Most Water
Letter Combinations of a Phone Number
Word Search
Find All Anagrams in a String
Minimum Height Trees
Task Scheduler
LRU Cache
Kth Smallest Element in a BST
Daily Temperatures
House Robber
Gas Station
Next Permutation
Valid Sudoku
Group Anagrams
Maximum Product Subarray
Design Add and Search Words Data Structure
Pacific Atlantic Water Flow
Remove Nth Node From End of List
Shortest Path to Get Food
Find the Duplicate Number
Top K Frequent Words
Longest Increasing Subsequence
Graph Valid Tree
Course Schedule II
Swap Node in Pairs
Path Sum II
Longest Consecutive Sequence
Rotate Array
Odd Even Linked List
Decode String
Contiguous Array
Maximum Width of Binary Tree
Find K Closest Elements
Longest Repeating Character Replacement
Inorder Successor in BST
Jump Game
Add Two Numbers
Generate Parentheses
Sort List
Number of Connected Components in an Undirected Graph
Minimum Knight Moves
Asteroid Collision
Subarray Sum Equals K
Random Pick with Weight
Kth Largest Element in an Array
Rotate Image
Binary Tree Zigzag Level Order Traversal
Design Hit Counter