Striver SDE Sheet

Striver's curated list of top coding interview problems. 180+ handpicked problems covering all DSA topics asked at Amazon, Google, Microsoft, and more.

Title	Solution	Practice	Difficulty	Companies	Topics
132. Palindrome Partitioning II	Solution	Solve	Hard	-	Dynamic Programming String
139. Word Break	Solution	Solve	Medium	-	Array Dynamic Programming+4
322. Coin Change	Solution	Solve	Medium	-	Array Breadth-First Search+1
5. Longest Palindromic Substring	Solution	Solve	Medium	-	Dynamic Programming String+1
13. Roman to Integer	Solution	Solve	Easy	-	Hash Table Math+1
14. Longest Common Prefix	Solution	Solve	Easy	-	String Trie
38. Count and Say	Solution	Solve	Medium	-	String
64. Minimum Path Sum	Solution	Solve	Medium	-	Array Dynamic Programming+1
72. Edit Distance	Solution	Solve	Medium	-	Dynamic Programming String
94. Binary Tree Inorder Traversal	Solution	Solve	Easy	-	Binary Tree Depth-First Search+2
98. Validate Binary Search Tree	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+2
100. Same Tree	Solution	Solve	Easy	-	Binary Tree Breadth-First Search+2
101. Symmetric Tree	Solution	Solve	Easy	-	Binary Tree Breadth-First Search+2
102. Binary Tree Level Order Traversal	Solution	Solve	Medium	-	Binary Tree Breadth-First Search+1
103. Binary Tree Zigzag Level Order Traversal	Solution	Solve	Medium	-	Binary Tree Breadth-First Search+1
104. Maximum Depth of Binary Tree	Solution	Solve	Easy	-	Binary Tree Breadth-First Search+2
105. Construct Binary Tree from Preorder and Inorder Traversal	Solution	Solve	Medium	-	Array Binary Tree+3
106. Construct Binary Tree from Inorder and Postorder Traversal	Solution	Solve	Medium	-	Array Binary Tree+3
108. Convert Sorted Array to Binary Search Tree	Solution	Solve	Easy	-	Array Binary Search Tree+3
110. Balanced Binary Tree	Solution	Solve	Easy	-	Binary Tree Depth-First Search+1
114. Flatten Binary Tree to Linked List	Solution	Solve	Medium	-	Binary Tree Depth-First Search+3
116. Populating Next Right Pointers in Each Node	Solution	Solve	Medium	-	Binary Tree Breadth-First Search+3
124. Binary Tree Maximum Path Sum	Solution	Solve	Hard	-	Binary Tree Depth-First Search+2
133. Clone Graph	Solution	Solve	Medium	-	Breadth-First Search Depth-First Search+2
144. Binary Tree Preorder Traversal	Solution	Solve	Easy	-	Binary Tree Depth-First Search+2
145. Binary Tree Postorder Traversal	Solution	Solve	Easy	-	Binary Tree Depth-First Search+2
151. Reverse Words in a String	Solution	Solve	Medium	-	String Two Pointers
152. Maximum Product Subarray	Solution	Solve	Medium	-	Array Dynamic Programming
155. Min Stack	Solution	Solve	Medium	-	Design Stack
165. Compare Version Numbers	Solution	Solve	Medium	-	String Two Pointers
173. Binary Search Tree Iterator	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+4
199. Binary Tree Right Side View	Solution	Solve	Medium	-	Binary Tree Breadth-First Search+2
200. Number of Islands	Solution	Solve	Medium	-	Array Breadth-First Search+3
207. Course Schedule	Solution	Solve	Medium	-	Breadth-First Search Depth-First Search+2
210. Course Schedule II	Solution	Solve	Medium	-	Breadth-First Search Depth-First Search+2
230. Kth Smallest Element in a BST	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+2
235. Lowest Common Ancestor of a Binary Search Tree	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+2
236. Lowest Common Ancestor of a Binary Tree	Solution	Solve	Medium	-	Binary Tree Depth-First Search+1
239. Sliding Window Maximum	Solution	Solve	Hard	-	Array Heap (Priority Queue)+3
242. Valid Anagram	Solution	Solve	Easy	-	Hash Table Sorting+1
285. Inorder Successor in BST	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+2
300. Longest Increasing Subsequence	Solution	Solve	Medium	-	Array Binary Search+1
333. Largest BST Subtree	Solution	Solve	Medium	-	Binary Search Tree Binary Tree+3
543. Diameter of Binary Tree	Solution	Solve	Easy	-	Binary Tree Depth-First Search+1
545. Boundary of Binary Tree	Solution	Solve	Medium	-	Binary Tree Depth-First Search+1
653. Two Sum IV - Input is a BST	Solution	Solve	Easy	-	Binary Search Tree Binary Tree+5
700. Search in a Binary Search Tree	Solution	Solve	Easy	-	Binary Search Tree Binary Tree+1
901. Online Stock Span	Solution	Solve	Medium	-	Data Stream Design+2
994. Rotting Oranges	Solution	Solve	Medium	-	Array Breadth-First Search+1
1008. Construct Binary Search Tree from Preorder Traversal	Solution	Solve	Medium	-	Array Binary Search Tree+4
1143. Longest Common Subsequence	Solution	Solve	Medium	-	Dynamic Programming String
1. Two Sum	Solution	Solve	Easy	-	Array Hash Table
2. Add Two Numbers	Solution	Solve	Medium	-	Linked List Math+1
3. Longest Substring Without Repeating Characters	Solution	Solve	Medium	-	Hash Table Sliding Window+1
4. Median of Two Sorted Arrays	Solution	Solve	Hard	-	Array Binary Search+1
15. 3Sum	Solution	Solve	Medium	-	Array Sorting+1
18. 4Sum	Solution	Solve	Medium	-	Array Sorting+1
19. Remove Nth Node From End of List	Solution	Solve	Medium	-	Linked List Two Pointers
20. Valid Parentheses	Solution	Solve	Easy	-	Stack String
21. Merge Two Sorted Lists	Solution	Solve	Easy	-	Linked List Recursion
23. Merge k Sorted Lists	Solution	Solve	Hard	-	Divide and Conquer Heap (Priority Queue)+2
25. Reverse Nodes in k-Group	Solution	Solve	Hard	-	Linked List Recursion
26. Remove Duplicates from Sorted Array	Solution	Solve	Easy	-	Array Two Pointers
31. Next Permutation	Solution	Solve	Medium	-	Array Two Pointers
33. Search in Rotated Sorted Array	Solution	Solve	Medium	-	Array Binary Search
37. Sudoku Solver	Solution	Solve	Hard	-	Array Backtracking+2
39. Combination Sum	Solution	Solve	Medium	-	Array Backtracking
40. Combination Sum II	Solution	Solve	Medium	-	Array Backtracking
42. Trapping Rain Water	Solution	Solve	Hard	-	Array Dynamic Programming+3
46. Permutations	Solution	Solve	Medium	-	Array Backtracking
48. Rotate Image	Solution	Solve	Medium	-	Array Math+1
50. Pow(x, n)	Solution	Solve	Medium	-	Math Recursion
51. N-Queens	Solution	Solve	Hard	-	Array Backtracking
53. Maximum Subarray	Solution	Solve	Medium	-	Array Divide and Conquer+1
56. Merge Intervals	Solution	Solve	Medium	-	Array Sorting
60. Permutation Sequence	Solution	Solve	Hard	-	Math Recursion
61. Rotate List	Solution	Solve	Medium	-	Linked List Two Pointers
62. Unique Paths	Solution	Solve	Medium	-	Combinatorics Dynamic Programming+1
74. Search a 2D Matrix	Solution	Solve	Medium	-	Array Binary Search+1
75. Sort Colors	Solution	Solve	Medium	-	Array Sorting+1
84. Largest Rectangle in Histogram	Solution	Solve	Hard	-	Array Monotonic Stack+1
88. Merge Sorted Array	Solution	Solve	Easy	-	Array Sorting+1
90. Subsets II	Solution	Solve	Medium	-	Array Backtracking+1
118. Pascal's Triangle	Solution	Solve	Easy	-	Array Dynamic Programming
121. Best Time to Buy and Sell Stock	Solution	Solve	Easy	-	Array Dynamic Programming
128. Longest Consecutive Sequence	Solution	Solve	Medium	-	Array Hash Table+1
131. Palindrome Partitioning	Solution	Solve	Medium	-	Backtracking Dynamic Programming+1
138. Copy List with Random Pointer	Solution	Solve	Medium	-	Hash Table Linked List
139. Word Break	Solution	Solve	Medium	-	Array Dynamic Programming+4
141. Linked List Cycle	Solution	Solve	Easy	-	Hash Table Linked List+1
142. Linked List Cycle II	Solution	Solve	Medium	-	Hash Table Linked List+1
146. LRU Cache	Solution	Solve	Medium	-	Design Doubly-Linked List+2
160. Intersection of Two Linked Lists	Solution	Solve	Easy	-	Hash Table Linked List+1
169. Majority Element	Solution	Solve	Easy	-	Array Counting+3
206. Reverse Linked List	Solution	Solve	Easy	-	Linked List Recursion
215. Kth Largest Element in an Array	Solution	Solve	Medium	-	Array Divide and Conquer+3
225. Implement Stack using Queues	Solution	Solve	Easy	-	Design Queue+1
229. Majority Element II	Solution	Solve	Medium	-	Array Counting+2
232. Implement Queue using Stacks	Solution	Solve	Easy	-	Design Queue+1
234. Palindrome Linked List	Solution	Solve	Easy	-	Linked List Recursion+2

Striver SDE Sheet

Palindrome Partitioning II

Word Break

Coin Change

Longest Palindromic Substring

Roman to Integer

Longest Common Prefix

Count and Say

Minimum Path Sum

Edit Distance

Binary Tree Inorder Traversal

Validate Binary Search Tree

Same Tree

Symmetric Tree

Binary Tree Level Order Traversal

Binary Tree Zigzag Level Order Traversal

Maximum Depth of Binary Tree

Construct Binary Tree from Preorder and Inorder Traversal

Construct Binary Tree from Inorder and Postorder Traversal

Convert Sorted Array to Binary Search Tree

Balanced Binary Tree

Flatten Binary Tree to Linked List

Populating Next Right Pointers in Each Node

Binary Tree Maximum Path Sum

Clone Graph

Binary Tree Preorder Traversal

Binary Tree Postorder Traversal

Reverse Words in a String

Maximum Product Subarray

Min Stack

Compare Version Numbers

Binary Search Tree Iterator

Binary Tree Right Side View

Number of Islands

Course Schedule

Course Schedule II

Kth Smallest Element in a BST

Lowest Common Ancestor of a Binary Search Tree

Lowest Common Ancestor of a Binary Tree

Sliding Window Maximum

Valid Anagram

Inorder Successor in BST

Longest Increasing Subsequence

Largest BST Subtree

Diameter of Binary Tree

Boundary of Binary Tree

Two Sum IV - Input is a BST

Search in a Binary Search Tree

Online Stock Span

Rotting Oranges

Construct Binary Search Tree from Preorder Traversal

Longest Common Subsequence

Two Sum

Add Two Numbers

Longest Substring Without Repeating Characters

Median of Two Sorted Arrays

3Sum

4Sum

Remove Nth Node From End of List

Valid Parentheses

Merge Two Sorted Lists

Merge k Sorted Lists

Reverse Nodes in k-Group

Remove Duplicates from Sorted Array

Next Permutation

Search in Rotated Sorted Array

Sudoku Solver

Combination Sum

Combination Sum II

Trapping Rain Water

Permutations

Rotate Image

Pow(x, n)

N-Queens

Maximum Subarray

Merge Intervals

Permutation Sequence

Rotate List

Unique Paths

Search a 2D Matrix