PT07Y  Is it a tree
You are given an unweighted, undirected graph. Write a program to check if it's a tree topology.
Input
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).
Output
Print YES if the given graph is a tree, otherwise print NO.
Example
Input: 3 2 1 2 2 3 Output: YES
hide comments
Shireen Nagdive:
20140709 11:45:30
Can anyone give hints how to solve the code without dfs and bfs? 

chin:
20140705 16:20:30
getting seg fault..:(


Manu Narsaria:
20140611 10:14:08
Submission ID:11738679


dragonemperor:
20140526 06:40:47
Weak test case. In none of the cases, number of edges is less than number of vertices. I have a condition that checks if number of edges is less than number of vertices minus 1. If it satisfies, my code is not taking edges as input but I still got AC. 

Suraj Rajan:
20140520 22:09:10
cycles and connectedness..!! :) 

Sudarshan K:
20140423 20:18:04
My very first DFS problem. :) 

sehwag:
20140411 18:37:26
easyone... Last edit: 20140411 18:40:52 

innovolt:
20140411 13:03:18
gud1 nd easy1 simple dfs 

Anubhav Balodhi :
20140329 21:25:37
Easier than I thought... agreed with both the points of @Rastogi.. 

heatOn:
20140317 11:59:31
No need for BFS or DFS !! easy one . 
Added by:  ThanhVy Hua 
Date:  20070328 
Time limit:  0.5s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO 
Resource:  Coauthor Amber 