POJ 2492 A Bug's Life (disjoint-set type)

A Bug's Life

Time Limit: 10000MS		Memory Limit: 65536K
Total Submissions: 52818		Accepted: 16983

Description

Background
Professor Hopper is researching the sexual behavior of a rare species of bugs. He assumes that they feature two different genders and that they only interact with bugs of the opposite gender. In his experiment, individual bugs and their interactions were easy to identify, because numbers were printed on their backs.
Problem
Given a list of bug interactions, decide whether the experiment supports his assumption of two genders with no homosexual bugs or if it contains some bug interactions that falsify it.

Input

The first line of the input contains the number of scenarios. Each scenario starts with one line giving the number of bugs (at least one, and up to 2000) and the number of interactions (up to 1000000) separated by a single space. In the following lines, each interaction is given in the form of two distinct bug numbers separated by a single space. Bugs are numbered consecutively starting from one.

Output

The output for every scenario is a line containing "Scenario #i:", where i is the number of the scenario starting at 1, followed by one line saying either "No suspicious bugs found!" if the experiment is consistent with his assumption about the bugs' sexual behavior, or "Suspicious bugs found!" if Professor Hopper's assumption is definitely wrong.

Sample Input

2
3 3
1 2
2 3
1 3
4 2
1 2
3 4

Sample Output

Scenario #1:
Suspicious bugs found!

Scenario #2:
No suspicious bugs found!

Topic effect and analysis

insects of n, m a relationship, each relationship on behalf of a and b can mate, there is no requirement to find bugs Gay

This and similar questions POJ1703, but also with the kind of disjoint-set to do for the ab input, query whether to belong to the same ancestor

 

#include <iostream>
#include <string.h>
#include <stdio.h>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <math.h>
#include <cstdio>
using namespace std;

int s[4005],t,n,m,k=0,flag;

int findf(int x)
{
    return x==s[x]?x:s[x]=findf(s[x]);
}

void hebing(int x,int y)
{
    int fx=findf(x);
    int fy=findf(y);
    if(fx!=fy)
    {
        s[fx]=fy;
    }
}

int main ()
{
    cin>>t;
    while(t--)
    {
        k++;
        flag=0;
        cin>>n>>m;
        for(int i=1;i<=2*n;i++)
        {
            s[i]=i;
        }
        while(m--)
        {
            int a,b;
            cin>>a>>b;
            if(findf(a)==findf(b))
            {
                flag=1;
            }
            else
            {
                hebing(a,b+n);
                hebing(a+n,b);
            }
        }
        cout<<"Scenario #"<<k<<":"<<endl;
        if(flag==1)
        {
            cout<<"Suspicious bugs found!"<<endl;
        }
        else
        {
            cout<<"No suspicious bugs found!"<<endl;
        }
        cout<<endl;
    }
}