Learn DSA from zero. Structured modules and coding challenges for absolute beginners.
11
Modules
52
Problems
15 / 34 / 3
Easy / Medium / Hard
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Big O & Complexity
Analyze how runtime and memory scale with input size. The foundation of every algorithm discussion.
The most fundamental data structures. Master traversal, two-pointer, sliding window, and in-place manipulation.
The most versatile data structure for O(1) lookups. Essential for counting, deduplication, and caching.
A linear sequence of nodes connected by pointers. Learn reversal, cycle detection, and fast/slow pointer patterns.
LIFO and FIFO structures fundamental to parsing, BFS/DFS, and monotonic patterns.
Problems that solve themselves: functions that call themselves. Essential for trees, graphs, and combinatorial search.
Every interview starts with sorting or searching. Master binary search variants and comparison-based sorting.
Make the locally optimal choice at each step. Works when local optimal choices lead to a global optimum.
Hierarchical data structures. Master recursion on trees and prefix-based search with tries.
Connections and relationships. BFS for shortest paths, DFS for connectivity, and topological sort for dependencies.
Optimization through memoization and tabulation. The hardest topic — but pattern recognition makes it solvable.