PT07Y - Is it a tree
You are given an unweighted, undirected graph. Write a program to check if it's a tree topology.
The first line of the input file contains two integers N and M --- number of nodes and number of edges in the graph (0 < N <= 10000, 0 <= M <= 20000). Next M lines contain M edges of that graph --- Each line contains a pair (u, v) means there is an edge between node u and node v (1 <= u,v <= N).
Print YES if the given graph is a tree, otherwise print NO.
Input: 3 2 1 2 2 3 Output: YES
|Added by:||Thanh-Vy Hua|
|Cluster:||Cube (Intel Pentium G860 3GHz)|
|Languages:||All except: ERL JS SCM chicken|
Got a lot of WA for writing "yes" and "no". Finally AC! :P
Dhruv Raj Singh Rathore:
what if graph is disjoint and separately both of them form a tree
how to solve without dfs?
union-find algorithm worked... :)
Last edit: 2014-08-16 14:30:58
[code removed by cyclops; see notes below, "1. Don't post any source code here."]Last edit: 2014-08-16 04:21:23
@jarvis this is a tree,
Please, what are some tricky test cases? I am getting WA, although the algorithm works fine for everything I come up with...
.:: Jarv1s ::.:
My first graph problem AC in first attempt