for each u ∈ G.V - {s} u.color = white s.color = red Q = ∅ Q.enqueue(s) while Q ≠ ∅ u = Q.dequeue() for each v ∈ G.Adj[u] if v.color = u.color output "not bipartite!" if v.color = white if u.color = blue v.color = red else v.color = blue Q.enqueue(v)