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 47 matching problems in SDE Sheet.

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All topics 0-1 Knapsack Array Backtracking Binary Search Binary Search Tree Binary Tree Boyer–Moore Majority Vote Algorithm Breadth-First Search Brute-Force Search Bucket Sort Combinatorics Complete Knapsack Counting Depth-First Search Directed Acyclic Graph Divide and Conquer DP on Trees Dynamic Programming

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Array30Dynamic Programming14Depth-First Search10

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

Title	Difficulty	Topics
1. Two Sum Open source	Easy	ArrayHash Table
15. 3Sum Open source	Medium	ArrayTwo PointersSorting
19. Remove Nth Node From End of List Open source	Medium	Linked ListTwo Pointers
21. Merge Two Sorted Lists Open source	Easy	Linked ListRecursion
31. Next Permutation Open source	Medium	ArrayTwo Pointers
33. Search in Rotated Sorted Array Open source	Medium	ArrayBinary Search
42. Trapping Rain Water Open source	Hard	ArrayTwo PointersDynamic Programming+2 more
48. Rotate Image Open source	Medium	ArrayMathMatrix
53. Maximum Subarray Open source	Medium	ArrayDivide and ConquerDynamic Programming
54. Spiral Matrix Open source	Medium	ArrayMatrixSimulation
56. Merge Intervals Open source	Medium	ArraySortingQuicksort
57. Insert Interval Open source	Medium	Array
62. Unique Paths Open source	Medium	MathDynamic ProgrammingCombinatorics
70. Climbing Stairs Open source	Easy	MathDynamic ProgrammingMemoization
73. Set Matrix Zeroes Open source	Medium	ArrayHash TableMatrix
74. Search a 2D Matrix Open source	Medium	ArrayBinary SearchMatrix
79. Word Search Open source	Medium	ArrayStringBacktracking+2 more
91. Decode Ways Open source	Medium	StringDynamic Programming
98. Validate Binary Search Tree Open source	Medium	TreeDepth-First SearchBinary Search Tree+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
110. Balanced Binary Tree Open source	Easy	TreeDepth-First SearchBinary Tree
118. Pascal's Triangle Open source	Easy	ArrayDynamic Programming
121. Best Time to Buy and Sell Stock Open source	Easy	ArrayDynamic Programming
128. Longest Consecutive Sequence Open source	Medium	ArrayHash TableUnion-Find