in Programming
2,592 views
0 votes
0 votes

In BFS of a directed graph, we don't have forward edges.Only tree edge,cross edge or back edge.

Below is a sample graph I have taken and classified edge types.

Please verify guys whether it's correct.

The algorithm I have used is the pseudocode given by "redtuna" in the selected answer here.

https://stackoverflow.com/questions/29631211/edge-classification-during-breadth-first-search-on-a-directed-graph

in Programming
2.6k views

4 Comments

Shaik Masthan plzz ellaborate ur line

mam, if it is a forward edge present , then it will recognize as tree edge at first step only 

0
0
Recognition of forward edge requires say for a Edge A->B, B should have been visited before the edge A-B is discovered and this can happen only when B is visited via some other vertex using more than one edge.Since, BFS finds shortest path from source in terms of smaller number of edges, When Vertex A is enqueued, edge A-B will be discovered and marked a tree or cross edge.Hence forward edges never possible.
1
1
What is forward edge? Let there is a tree edge between A to B and B to C then A --> C is a forward edge, think  that At A itself C is pushed into queue then there is no chance of A --> C is look as forward edge
2
2

1 Answer

0 votes
0 votes

Watch this, It may help to understand the concept of edges

Related questions

2 votes
2 votes
0 answers
3