Breadth First Search

Notes

• Note this algorithm is from CLRS and probably has more information that you are used to.
  • π is the parent of a vertex
  • color is the status of a vertex
  • d is the depth of a vertex in the bfs-tree
• We will use this information in future algorithms.

• BFS(G,s)
     Input:  a graph G = (V,E)
             s ∈ V, a starting point
     Output: a search tree
             all "reachable" vertexes labeled/identified
             information about the bfs-tree
  
   for each vertex u ∈ G.V - {s}
        u.color = WHITE
        u.d = ∞
        u.π = NIL 
   s.color = GRAY
   s.d = 0
   s.π = NIL
   Make an empty queue Q
   Q.enqueue(s)
   While not Q.isEmpty
      u = Q.Dequeue
      for each v ∈ G.Adj(u)
      if v.color == WHITE
         v.color = GRAY
         v.d = u.d + 1
         v.π = u
         Q.Enqueue(v)
      u.color = BLACK
  
       
   What does this do?
       
   Is it correct?
       
   What is the performance?