Zero To DSA

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 and monotonic patterns.

Problems that solve themselves: functions that call themselves. Essential for combinatorial search and divide-and-conquer algorithms.

Every interview starts with sorting or searching. Master binary search variants and comparison-based sorting.

Hierarchical data structures. Master recursion on trees and prefix-based search with tries.

Make the locally optimal choice at each step. Works when local optimal choices lead to a global optimum.

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.