Breadth-first search

Pseudocode

BFS(G,s)
 1 for each vertex u ∈ G.V - {s}
 2       u.color = WHITE
 3       u.d = ∞
 4       u.π = NIL
 5 s.color = GRAY
 6 s.d = 0
 7 s.π = NIL
 8 Q = Ø
 9 ENQUE(Q, s)
10 while Q ≠ Ø
11      u = DEQUEUE(Q)
12      for each v ∈ G.Adj[u]
13              if v.color == WHITE
14                       v.color = GRAY
15                       v.d = u.d + 1
16                       v.π = u
17                       ENQUEUE(Q, v)
18      u.color = BLACK