BFS

 1    Breadth-First-Search(Graph, root):
 2 
 3     for each node n in Graph:            
 4        n.distance = INFINITY        
 5        n.parent = NIL
 6 
 7     create empty queue Q      
 8 
 9    root.distance = 0
10   Q.enqueue(root)                      
11 
12   while Q is not empty:        
13     
14       current = Q.dequeue()
15     
16       for each node n that is adjacent to current:
17           if n.distance == INFINITY:
18               n.distance = current.distance + 1
19               n.parent = current
20              Q.enqueue(n)