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
201. Bitwise AND of Numbers Range	Solve	Medium	Adobe	Bit Manipulation
202. Happy Number	Solve	Easy	Adobe+5	Hash Table Math+1
203. Remove Linked List Elements	Solve	Easy	Adobe+3	Linked List Recursion
204. Count Primes	Solve	Medium	Adobe+6	Array Enumeration+2
205. Isomorphic Strings	Solve	Easy	Amazon+2	Hash Table String
206. Reverse Linked List	Solve	Easy	Amazon+8	Linked List Recursion
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
212. Word Search II	Solve	Hard	Amazon+9	Array Backtracking+3
213. House Robber II	Solve	Medium	Amazon+1	Array Dynamic Programming
214. Shortest Palindrome	Solve	Hard	Apple+3	Hash Function Rolling Hash+2
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
217. Contains Duplicate	Solve	Easy	Adobe+8	Array Hash Table+1
218. The Skyline Problem	Solve	Hard	Cruise Automation+3	Array Binary Indexed Tree+5
219. Contains Duplicate II	Solve	Easy	Adobe+6	Array Hash Table+1
220. Contains Duplicate III	Solve	Hard	Adobe+3	Array Bucket Sort+3
221. Maximal Square	Solve	Medium	Amazon+7	Array Dynamic Programming+1
222. Count Complete Tree Nodes	Solve	Easy	Amazon+2	Binary Search Binary Tree+2
223. Rectangle Area	Solve	Medium	Amazon	Geometry Math
224. Basic Calculator	Solve	Hard	Adobe+8	Math Recursion+2
225. Implement Stack using Queues	Solve	Easy	Accenture+54	Design Queue+1
226. Invert Binary Tree	Solve	Easy	Amazon+5	Binary Tree Breadth-First Search+2
227. Basic Calculator II	Solve	Medium	Amazon+9	Math Stack+1
228. Summary Ranges	Solve	Easy	Adobe+7	Array
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
231. Power of Two	Solve	Easy	Amazon+3	Bit Manipulation Math+1
232. Implement Queue using Stacks	Solve	Easy	Amazon+4	Design Queue+1
233. Number of Digit One	Solve	Hard	Google+1	Dynamic Programming Math+1
234. Palindrome Linked List	Solve	Easy	Adobe+10	Linked List Recursion+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
239. Sliding Window Maximum	Solve	Hard	Accion Labs India+66	Array Heap (Priority Queue)+3
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
242. Valid Anagram	Solve	Easy	Affirm+8	Hash Table Sorting+1
243. Shortest Word Distance	Solve	Easy	Amazon+4	Array String
244. Shortest Word Distance II	Solve	Medium	LinkedIn	Array Design+3
245. Shortest Word Distance III	Solve	Medium	Amazon+1	Array String
246. Strobogrammatic Number	Solve	Easy	Facebook+1	Hash Table String+1
247. Strobogrammatic Number II	Solve	Medium	Facebook+2	Array Recursion+1
248. Strobogrammatic Number III	Solve	Hard	Google	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