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bridge / critical links

Posted: Sun Jun 18, 2006 9:25 pm
by asif_rahman0
Undirected graph. ok.
"Critical link is an egde whose removal disconnects a graph(G)."

1->2
1->4
4->3
2->5
3->2
3->10
3->9
5->6
5->7
7->8
5->8
8->2
2->7

here is a graph of 13 edges.
now my question is how many bridge or critical links is here?
i think here is only --->
3-10
3-9
5-6
Am i right?

but here is a problem about vertex 2. It is an articulation point but not critical link?? may be i m missing something!!!

plz help.

Posted: Mon Jun 19, 2006 8:37 am
by misof
You are right.

An equivalent definition: edge is a bridge if and only if it is not a part of any cycle. In your graph, the edges 3-9, 3-10, and 5-6 are bridges.

A vertex is an articulation point (somewhere you can see also the name "cutvertex") if and only if its removal increases the number of components.

In your graph, articulation points are the vertices 2, 3, and 5.

Posted: Mon Jun 19, 2006 3:26 pm
by asif_rahman0
Thnx misof. Just learned the name of CutVertex from you:). Before i dont know it.

Now i am confident about it. And also i coded 796(critical links).
But getting WA.

Could you send me some input output in PM or here?

please help.

Posted: Mon Jun 19, 2006 4:59 pm
by Moheeb
Asif wrote:
Thnx misof. Just learned the name of CutVertex from you:). Before i dont know it.

Really ? u shouldn't go too far to know about it, look at Rosen's Discrete book,
section 8.4 , example 7 . BTW, this problem is really easy. :wink: