Adjacency Matrix
Domain: Data Structures
🎯 Motivation
For dense graphs (many edges) or when you need to check edge existence instantly, a matrix stores all possible connections as a table.
📋 Concrete Example
A 4x4 grid where matrix[i][j] = 1 means node i connects to node j, 0 means no connection. Checking matrix[2][3] is O(1).
🔗 Analogy
A seating chart for a classroom showing who sits next to whom. Every possible pair has a yes or no in a grid. Quick to look up but wastes space if few students sit together.