Breadth First Search (BFS) in Graph

Traversing in Graph

Graph traversal is technique used for visit all the vertex in a graph. The graph traversal is also used to decide the order of vertices to be visit in the search process. A graph traversal finds the edges to be used in the search process without creating loops that means using graph traversal we visit all vertices of graph without getting into looping path.

Graph Traversal done by Two Techniques.

1. DFS (Depth First Search) 
2. BFS (Breadth First Search)

Breadth First Search (BFS) algorithm traverses a graph in a breadth-ward motion and uses a queue to remember to get the next vertex to start a search, when a dead end occurs in any iteration.

We use the following steps to implement BFS traversal...

Step 1: Define a Queue of size total number of vertices in the graph.

Step 2: Select any vertex as starting point for traversal. Visit that vertex and insert it into the Queue.

Step 3: Visit all the adjacent vertices of the verex which is at front of the Queue which is not visited and insert them into the Queue.

Step 4: When there is no new vertex to be visit from the vertex at front of the Queue then delete that vertex from the Queue.

Step 5: Repeat step 3 and 4 until queue becomes empty.


Step 6: When queue becomes Empty, then produce final spanning tree by removing unused edges from the graph

To know about the implementation of this algorithm in C programming language click here