Dashboard Questions Topics Companies Sheets

Data Structures & Algorithms

Practice 3,374+ coding problems from top companies. Master DSA concepts and ace your interviews.

3,374

Problems

840

Easy

1762

Medium

772

Hard

Difficulty

All3374 Easy840 Medium1762 Hard772

Title	Solve	Difficulty	Companies	Topics
167. Two Sum II - Input Array Is Sorted	Solve	Medium	Adobe+5	Array Binary Search+1
172. Factorial Trailing Zeroes	Solve	Medium	Amazon+1	Math
173. Binary Search Tree Iterator	Solve	Medium	Amazon+5	Binary Search Tree Binary Tree+4
176. Second Highest Salary	Solve	Medium	Accenture+10	Database
177. Nth Highest Salary	Solve	Medium	Adobe+2	Database
178. Rank Scores	Solve	Medium	Adobe+4	Database
179. Largest Number	Solve	Medium	Adobe+8	Array Greedy+2
180. Consecutive Numbers	Solve	Medium	Adobe+4	Database
184. Department Highest Salary	Solve	Medium	Adobe+3	Database
186. Reverse Words in a String II	Solve	Medium	Microsoft	String Two Pointers
187. Repeated DNA Sequences	Solve	Medium	Amazon+1	Bit Manipulation Hash Function+4
189. Rotate Array	Solve	Medium	Amazon+6	Array Math+1
192. Word Frequency	Solve	Medium	-	Shell
194. Transpose File	Solve	Medium	-	Shell
198. House Robber	Solve	Medium	Adobe+8	Array Dynamic Programming
199. Binary Tree Right Side View	Solve	Medium	Amazon+8	Binary Tree Breadth-First Search+2
200. Number of Islands	Solve	Medium	Adobe+40	Array Breadth-First Search+3
201. Bitwise AND of Numbers Range	Solve	Medium	Adobe	Bit Manipulation
204. Count Primes	Solve	Medium	Adobe+6	Array Enumeration+2
207. Course Schedule	Solve	Medium	Amazon+8	Breadth-First Search Depth-First Search+2
208. Implement Trie (Prefix Tree)	Solve	Medium	Amazon+8	Design Hash Table+2
209. Minimum Size Subarray Sum	Solve	Medium	Amazon+7	Array Binary Search+2
210. Course Schedule II	Solve	Medium	Amazon+14	Breadth-First Search Depth-First Search+2
211. Design Add and Search Words Data Structure	Solve	Medium	Amazon+6	Depth-First Search Design+2
213. House Robber II	Solve	Medium	Amazon+1	Array Dynamic Programming
215. Kth Largest Element in an Array	Solve	Medium	ABCO+44	Array Divide and Conquer+3
216. Combination Sum III	Solve	Medium	Google	Array Backtracking
221. Maximal Square	Solve	Medium	Amazon+7	Array Dynamic Programming+1
223. Rectangle Area	Solve	Medium	Amazon	Geometry Math
227. Basic Calculator II	Solve	Medium	Amazon+9	Math Stack+1
229. Majority Element II	Solve	Medium	Accolite+21	Array Counting+2
230. Kth Smallest Element in a BST	Solve	Medium	Amazon+4	Binary Search Tree Binary Tree+2
235. Lowest Common Ancestor of a Binary Search Tree	Solve	Medium	Amazon+5	Binary Search Tree Binary Tree+2
236. Lowest Common Ancestor of a Binary Tree	Solve	Medium	Amazon+9	Binary Tree Depth-First Search+1
237. Delete Node in a Linked List	Solve	Medium	Amazon+1	Linked List
238. Product of Array Except Self	Solve	Medium	Adobe+8	Array Prefix Sum
240. Search a 2D Matrix II	Solve	Medium	Amazon+5	Array Binary Search+2
241. Different Ways to Add Parentheses	Solve	Medium	Bloomberg+2	Dynamic Programming Math+3
244. Shortest Word Distance II	Solve	Medium	LinkedIn	Array Design+3
245. Shortest Word Distance III	Solve	Medium	Amazon+1	Array String
247. Strobogrammatic Number II	Solve	Medium	Facebook+2	Array Recursion+1
249. Group Shifted Strings	Solve	Medium	Facebook+1	Array Hash Table+1
250. Count Univalue Subtrees	Solve	Medium	Google+1	Binary Tree Depth-First Search+1
251. Flatten 2D Vector	Solve	Medium	Airbnb	Array Design+2
253. Meeting Rooms II	Solve	Medium	Amazon+8	Array Greedy+4
254. Factor Combinations	Solve	Medium	LinkedIn	Backtracking
255. Verify Preorder Sequence in Binary Search Tree	Solve	Medium	Oracle+2	Array Binary Search Tree+5
256. Paint House	Solve	Medium	Amazon+2	Array Dynamic Programming
259. 3Sum Smaller	Solve	Medium	Apple+2	Array Binary Search+2
260. Single Number III	Solve	Medium	Google	Array Bit Manipulation