LeetCode 785 Is Graph Bipartite? - Lessons

Four things to remember:

$1.$ Use an array to track colors. Initialize to $-1$ for "unvisited."

$2.$ The color flip trick 1 - c alternates between $0$ and $1$ cleanly.

$3.$ Check all neighbors: if same color, return false immediately.

$4.$ Handle disconnected graphs with an outer loop over all nodes.

This is the core bipartite detection pattern. Every variation uses the same idea: try to $2$-color, fail if you find a conflict.