POJ 2492 A Bug's Life (并查集)

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<string>
#include<iostream>
#include<cstring>
#include<cmath>
#include<stack>
#include<queue>
#include<vector>
#include<map>
#include<stdlib.h>
#include<algorithm>
#define LL __int64
using namespace std;
const int MAXN=2000+5;
int p[MAXN],w[MAXN];
int kase,n,m;
bool flag;

void init()
{
    memset(p,-1,sizeof(p));
    memset(w,0,sizeof(w));
    flag=false;
}
int findfa(int x)
{
    if(p[x]==-1) return x;
    int tmp=p[x];
    p[x]=findfa(p[x]);
    w[x]=(w[x]+w[tmp])%2;
    return p[x];
}
int main()
{
    //freopen("in.txt","r",stdin);
    int Case=0;
    scanf("%d",&kase);
    while(kase--)
    {
        scanf("%d %d",&n,&m);
        init();
        for(int i=0;i<m;i++)
        {
            int u,v;
            scanf("%d %d",&u,&v);
            int x=findfa(u);
            int y=findfa(v);

            if(flag) continue;

            if(x==y)
            {
                if(w[u]==w[v])
                    flag=true;
            }
            else
            {
                p[y]=x;
                w[y]=(1-w[u]-w[v]+2)%2;
            }
        }
        printf("Scenario #%d:\n",++Case);
        if(flag) printf("Suspicious bugs found!\n\n");
        else printf("No suspicious bugs found!\n\n");
    }
    return 0;
}