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 26-50 of 80 matching problems in NeetCode 150.

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Array80Dynamic Programming35String33

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

Title	Difficulty	Topics
90. Subsets II Open source	Medium	ArrayBacktrackingBit Manipulation
105. Construct Binary Tree from Preorder and Inorder Traversal Open source	Medium	ArrayHash TableDivide and Conquer+2 more
121. Best Time to Buy and Sell Stock Open source	Easy	ArrayDynamic Programming
128. Longest Consecutive Sequence Open source	Medium	ArrayHash TableUnion-Find
130. Surrounded Regions Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more
134. Gas Station Open source	Medium	ArrayGreedy
136. Single Number Open source	Easy	ArrayBit Manipulation
139. Word Break Open source	Medium	ArrayHash TableString+4 more
150. Evaluate Reverse Polish Notation Open source	Medium	ArrayMathStack
152. Maximum Product Subarray Open source	Medium	ArrayDynamic Programming
153. Find Minimum in Rotated Sorted Array Open source	Medium	ArrayBinary Search
167. Two Sum II - Input Array Is Sorted Open source	Medium	ArrayTwo PointersBinary Search
198. House Robber Open source	Medium	ArrayDynamic Programming
200. Number of Islands Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 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
238. Product of Array Except Self Open source	Medium	ArrayPrefix Sum
239. Sliding Window Maximum Open source	Hard	ArrayQueueSliding Window+3 more
252. Meeting Rooms Open sourcePremium	Easy	ArraySortingQuicksort
253. Meeting Rooms II Open sourcePremium	Medium	ArrayTwo PointersGreedy+3 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