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 126-150 of 250 matching problems in NeetCode 250.

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All topics 0-1 Knapsack Algorithm X Array Backtracking Bellman–Ford Algorithm Bidirectional Search Binary Lifting Binary Search Binary Search Tree Binary Tree Bit Manipulation Bitmask Borůvka's Algorithm Boyer–Moore Majority Vote Algorithm Bracket Sequences Breadth-First Search Brute-Force Search Bubble Sort

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Array141Dynamic Programming55String53

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

Title	Difficulty	Topics
238. Product of Array Except Self Open source	Medium	ArrayPrefix Sum
239. Sliding Window Maximum Open source	Hard	ArrayQueueSliding Window+3 more
242. Valid Anagram Open source	Easy	Hash TableStringSorting
252. Meeting Rooms Open sourcePremium	Easy	ArraySortingQuicksort
253. Meeting Rooms II Open sourcePremium	Medium	ArrayTwo PointersGreedy+3 more
261. Graph Valid Tree Open sourcePremium	Medium	Depth-First SearchBreadth-First SearchUnion-Find+1 more
268. Missing Number Open source	Easy	ArrayHash TableMath+3 more
269. Alien Dictionary Open sourcePremium	Hard	ArrayStringDepth-First Search+4 more
271. Encode and Decode Strings Open sourcePremium	Medium	ArrayStringDesign
279. Perfect Squares Open source	Medium	MathDynamic ProgrammingBreadth-First Search+2 more
286. Walls and Gates Open sourcePremium	Medium	ArrayBreadth-First SearchMatrix
287. Find the Duplicate Number Open source	Medium	ArrayTwo PointersBinary Search+3 more
295. Find Median from Data Stream Open source	Hard	Two PointersDesignSorting+2 more
297. Serialize and Deserialize Binary Tree Open source	Hard	StringTreeDepth-First Search+3 more
300. Longest Increasing Subsequence Open source	Medium	ArrayBinary SearchDynamic Programming+1 more
304. Range Sum Query 2D - Immutable Open source	Medium	ArrayDesignMatrix+1 more
309. Best Time to Buy and Sell Stock with Cooldown Open source	Medium	ArrayDynamic Programming
310. Minimum Height Trees Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+1 more
312. Burst Balloons Open source	Hard	ArrayDynamic Programming
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
332. Reconstruct Itinerary Open source	Hard	ArrayStringDepth-First Search+6 more
337. House Robber III Open source	Medium	Dynamic ProgrammingTreeDepth-First Search+2 more
338. Counting Bits Open source	Easy	Dynamic ProgrammingBit Manipulation