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 76-100 of 150 matching problems in NeetCode 150.

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All topics 0-1 Knapsack Algorithm X Array Backtracking Bidirectional Search Binary Lifting Binary Search Binary Search Tree Binary Tree Bit Manipulation Borůvka's Algorithm Bracket Sequences Breadth-First Search Brute-Force Search Bucket Sort Combinatorics Complete Knapsack Counting

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Array80Dynamic Programming35String33

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

Title	Difficulty	Topics
198. House Robber Open source	Medium	ArrayDynamic Programming
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
202. Happy Number Open source	Easy	Hash TableMathTwo Pointers+1 more
206. Reverse Linked List Open source	Easy	Linked ListRecursion
207. Course Schedule Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+2 more
208. Implement Trie (Prefix Tree)Open source	Medium	Hash TableStringDesign+1 more
210. Course Schedule II Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+1 more
211. Design Add and Search Words Data Structure Open source	Medium	StringDepth-First SearchDesign+1 more
212. Word Search II Open source	Hard	ArrayStringBacktracking+2 more
213. House Robber II Open source	Medium	ArrayDynamic Programming
215. Kth Largest Element in an Array Open source	Medium	ArrayDivide and ConquerSorting+2 more
217. Contains Duplicate Open source	Easy	ArrayHash TableSorting
226. Invert Binary Tree Open source	Easy	TreeDepth-First SearchBreadth-First Search+1 more
230. Kth Smallest Element in a BST Open source	Medium	TreeDepth-First SearchBinary Search Tree+1 more
235. Lowest Common Ancestor of a Binary Search Tree Open source	Medium	TreeDepth-First SearchBinary Search Tree+3 more
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