Problem Library

Master these coding challenges to ace your next technical interview. Handpicked problems with personalized spaced repetition.

Showing 1-10 of 10 matching problems in SDE Sheet.

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Array30Dynamic Programming14Depth-First Search10

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

Title	Difficulty	Topics
79. Word Search Open source	Medium	ArrayStringBacktracking+2 more
98. Validate Binary Search Tree Open source	Medium	TreeDepth-First SearchBinary Search Tree+1 more
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
133. Clone Graph Open source	Medium	Hash TableDepth-First SearchBreadth-First Search+1 more
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
207. Course Schedule Open source	Medium	Depth-First SearchBreadth-First SearchGraph Theory+2 more
230. Kth Smallest Element in a BST Open source	Medium	TreeDepth-First SearchBinary Search Tree+1 more
543. Diameter of Binary Tree Open source	Easy	TreeDepth-First SearchBinary Tree+1 more