Problem Library

Master these coding challenges to ace your next technical interview. Handpicked problems with personalized spaced repetition.

All tracks Blind 75 NeetCode 150 NeetCode 250 Striver A to Z SDE Sheet

Showing 1-25 of 34 matching problems in NeetCode 250.

Topic focus

Array141Dynamic Programming55String53

These are the topics showing up most often in your current queue.

Title	Difficulty	Topics
100. Same Tree Open source	Easy	TreeDepth-First SearchBreadth-First Search+1 more
102. Binary Tree Level Order Traversal Open source	Medium	TreeBreadth-First SearchBinary Tree
104. Maximum Depth of Binary Tree Open source	Easy	TreeDepth-First SearchBreadth-First Search+1 more
127. Word Ladder Open source	Hard	Hash TableStringBreadth-First Search+1 more
130. Surrounded Regions Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more
133. Clone Graph Open source	Medium	Hash TableDepth-First SearchBreadth-First Search+1 more
199. Binary Tree Right Side View Open source	Medium	TreeDepth-First SearchBreadth-First Search+1 more
200. Number of Islands Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more
207. Course Schedule Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+2 more
210. Course Schedule II Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+1 more
226. Invert Binary Tree Open source	Easy	TreeDepth-First SearchBreadth-First Search+1 more
261. Graph Valid Tree Open sourcePremium	Medium	Depth-First SearchBreadth-First SearchUnion-Find+1 more
269. Alien Dictionary Open sourcePremium	Hard	ArrayStringDepth-First Search+4 more
279. Perfect Squares Open source	Medium	MathDynamic ProgrammingBreadth-First Search+2 more
286. Walls and Gates Open sourcePremium	Medium	ArrayBreadth-First SearchMatrix
297. Serialize and Deserialize Binary Tree Open source	Hard	StringTreeDepth-First Search+3 more
310. Minimum Height Trees Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+1 more
322. Coin Change Open source	Medium	ArrayDynamic ProgrammingBreadth-First Search+2 more
323. Number of Connected Components in an Undirected Graph Open sourcePremium	Medium	Depth-First SearchBreadth-First SearchUnion-Find+1 more
329. Longest Increasing Path in a Matrix Open source	Hard	ArrayDynamic ProgrammingDepth-First Search+6 more
399. Evaluate Division Open source	Medium	ArrayStringDepth-First Search+6 more
417. Pacific Atlantic Water Flow Open source	Medium	ArrayDepth-First SearchBreadth-First Search+1 more
463. Island Perimeter Open source	Easy	ArrayDepth-First SearchBreadth-First Search+1 more
684. Redundant Connection Open source	Medium	Depth-First SearchBreadth-First SearchUnion-Find+1 more
695. Max Area of Island Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more