Problem catalog
All DSA Problems
75 curated coding problems across 16 categories. Every problem opens in a local-first workspace with starter templates and a verified solution in C++, Java, Python, and Go.
Easy
19
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Medium
49
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Hard
7
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Topics
16
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Arrays & Hashing· 11
Two Pointers· 3
Sliding Window· 4
Stack· 1
Binary Search· 2
Linked List· 5
Trees· 11
Maximum Depth of Binary TreeeasySame TreeeasyInvert Binary TreeeasyBinary Tree Maximum Path SumhardBinary Tree Level Order TraversalmediumSerialize and Deserialize Binary TreehardSubtree of Another TreeeasyConstruct Binary Tree from Preorder and Inorder TraversalmediumValidate Binary Search TreemediumKth Smallest Element in a BSTmediumLowest Common Ancestor of a Binary Search Treemedium
Tries· 3
Heap / Priority Queue· 3
Backtracking· 1
Graphs· 7
Dynamic Programming· 13
Maximum Product SubarraymediumClimbing StairseasyCoin ChangemediumLongest Increasing SubsequencemediumLongest Common SubsequencemediumWord BreakmediumCombination Sum IVmediumHouse RobbermediumHouse Robber IImediumDecode WaysmediumUnique PathsmediumLongest Palindromic SubstringmediumPalindromic Substringsmedium