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|
A simple loop with parents array is enough .. no need for DFS or BFS or any graph traversal algo
Learnt Union Find :)
how to solve without using dfs.
tle with dfs, bfs works fine
Union Find rocks!!
simple bfs ^ - ^
I used Union Find, it's really nice.
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?