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 51-75 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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Title	Difficulty	Topics
105. Construct Binary Tree from Preorder and Inorder Traversal Open source	Medium	ArrayHash TableDivide and Conquer+2 more
110. Balanced Binary Tree Open source	Easy	TreeDepth-First SearchBinary Tree
115. Distinct Subsequences Open source	Hard	StringDynamic Programming
121. Best Time to Buy and Sell Stock Open source	Easy	ArrayDynamic Programming
124. Binary Tree Maximum Path Sum Open source	Hard	Dynamic ProgrammingTreeDepth-First Search+2 more
125. Valid Palindrome Open source	Easy	Two PointersString
127. Word Ladder Open source	Hard	Hash TableStringBreadth-First Search+1 more
128. Longest Consecutive Sequence Open source	Medium	ArrayHash TableUnion-Find
130. Surrounded Regions Open source	Medium	ArrayDepth-First SearchBreadth-First Search+2 more
131. Palindrome Partitioning Open source	Medium	StringDynamic ProgrammingBacktracking
133. Clone Graph Open source	Medium	Hash TableDepth-First SearchBreadth-First Search+1 more
134. Gas Station Open source	Medium	ArrayGreedy
136. Single Number Open source	Easy	ArrayBit Manipulation
138. Copy List with Random Pointer Open source	Medium	Hash TableLinked List
139. Word Break Open source	Medium	ArrayHash TableString+4 more
141. Linked List Cycle Open source	Easy	Hash TableLinked ListTwo Pointers+1 more
143. Reorder List Open source	Medium	Linked ListTwo PointersStack+1 more
146. LRU Cache Open source	Medium	Hash TableLinked ListDesign+1 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
155. Min Stack Open source	Medium	StackDesign
167. Two Sum II - Input Array Is Sorted Open source	Medium	ArrayTwo PointersBinary Search
190. Reverse Bits Open source	Easy	Divide and ConquerBit Manipulation
191. Number of 1 Bits Open source	Easy	Divide and ConquerBit Manipulation