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Top 107 LeetCode Questions

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Arrays & Strings

#	Question	Difficulty	Solved
1	Two Sum	Easy
2	Best Time to Buy and Sell Stock	Easy
3	Maximum Subarray	Medium
4	Rotate Array	Medium
5	Set Matrix Zeroes	Medium
6	Container With Most Water	Medium
7	Product of Array Except Self	Medium
8	Longest Substring Without Repeating Characters	Medium
9	Valid Palindrome	Medium
10	Sliding Window Maximum	Hard

Hashing & Prefix Sum

#	Question	Difficulty	Solved
1	Subarray Sum Equals K	Medium
2	Valid Anagram	Easy
3	Group Anagrams	Medium
4	Two Sum II - Input Array Is Sorted	Easy
5	Find All Anagrams in a String	Medium
6	Minimum Window Substring	Hard
7	Range Sum Query - Immutable	Easy
8	Maximum Average Subarray I	Easy
9	3Sum	Medium
10	4Sum	Medium

Linked List

#	Question	Difficulty	Solved
1	Reverse Linked List	Easy
2	Merge Two Sorted Lists	Easy
3	Linked List Cycle	Easy
4	Intersection of Two Linked Lists	Easy
5	Remove Nth Node From End of List	Medium
6	Reorder List	Medium
7	Add Two Numbers	Medium
8	Copy List with Random Pointer	Medium
9	LRU Cache	Medium
10	Merge k Sorted Lists	Hard

Stack & Queue

#	Question	Difficulty	Solved
1	Valid Parentheses	Easy
2	Min Stack	Medium
3	Evaluate Reverse Polish Notation	Medium
4	Daily Temperatures	Medium
5	Implement Queue using Stacks	Easy
6	Implement Stack using Queues	Easy
7	Next Greater Element I	Easy
8	Largest Rectangle in Histogram	Hard
9	Design Circular Queue	Medium
10	Sliding Window Maximum	Hard

Binary Trees & BST

#	Question	Difficulty	Solved
1	Maximum Depth of Binary Tree	Easy
2	Same Tree	Easy
3	Invert Binary Tree	Easy
4	Diameter of Binary Tree	Easy
5	Balanced Binary Tree	Easy
6	Path Sum	Easy
7	Binary Tree Level Order Traversal	Medium
8	Construct Binary Tree from Preorder and Inorder Traversal	Medium
9	Binary Tree Zigzag Level Order Traversal	Medium
10	Lowest Common Ancestor of a Binary Tree	Medium
11	Serialize and Deserialize Binary Tree	Hard
12	Validate Binary Search Tree	Medium
13	Kth Smallest Element in a BST	Medium
14	Binary Search Tree Iterator	Medium
15	Recover Binary Search Tree	Hard

Recursion & Backtracking

#	Question	Difficulty	Solved
1	Subsets	Medium
2	Combination Sum	Medium
3	Permutations	Medium
4	Word Search	Medium
5	Palindrome Partitioning	Medium
6	N-Queens	Hard
7	Letter Combinations of a Phone Number	Medium
8	Generate Parentheses	Medium

Dynamic Programming

#	Question	Difficulty	Solved
1	Climbing Stairs	Easy
2	House Robber	Medium
3	House Robber II	Medium
4	Coin Change	Medium
5	Longest Increasing Subsequence	Medium
6	Partition Equal Subset Sum	Medium
7	Unique Paths	Medium
8	Minimum Path Sum	Medium
9	Edit Distance	Hard
10	Word Break	Medium
11	Longest Palindromic Subsequence	Medium
12	Longest Common Subsequence	Medium
13	Maximum Product Subarray	Medium
14	Burst Balloons	Hard
15	Interleaving String	Hard

Graphs

#	Question	Difficulty	Solved
1	Number of Islands	Medium
2	Clone Graph	Medium
3	Course Schedule	Medium
4	Course Schedule II	Medium
5	Pacific Atlantic Water Flow	Medium
6	Word Ladder	Hard
7	Rotting Oranges	Medium
8	Graph Valid Tree	Medium
9	Shortest Path in Binary Matrix	Medium
10	Network Delay Time	Medium

Tries / Advanced

#	Question	Difficulty	Solved
1	Implement Trie (Prefix Tree)	Medium
2	Design Add and Search Words Data Structure	Medium
3	Word Search II	Hard

Bit Manipulation / Math / Binary Search

#	Question	Difficulty	Solved
1	Single Number	Easy
2	Number of 1 Bits	Easy
3	Counting Bits	Medium
4	Pow(x, n)	Medium
5	Sqrt(x)	Easy
6	Search in Rotated Sorted Array	Medium
7	Search a 2D Matrix	Medium
8	Counting Bits	Medium
9	Divide Two Integers	Medium
10	Power of Two	Easy