A Bug's Life POJ - 2492 （带权并查集）

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<sstream>
#include<cmath>
#include<stack>
#include<map>
#include<cstdlib>
#include<vector>
#include<string>
#include<queue>
using namespace std;

#define ll long long
#define llu unsigned long long
#define INF 0x3f3f3f3f
const double PI = acos(-1.0);
const int maxn =  5e4+10;
const int mod = 1e9+7;

struct node
{
    int pre;
    int relation;  //0:同 1:异
}p[maxn];

int find(int x)
{
    int temp;
    if(x == p[x].pre)
        return x;
    temp = p[x].pre;
    p[x].pre = find(temp);
    p[x].relation = (p[x].relation + p[temp].relation + 1) % 2;
    return p[x].pre;
}
void combine(int x,int y)
{
    int xx = find(x);
    int yy = find(y);
    if(xx != yy)
    {
        p[xx].pre = yy;
        p[xx].relation = (p[y].relation - p[x].relation) % 2;
    }
}
int main()
{
   int t;
   scanf("%d",&t);
   int ca=1;
   while(t--)
   {
       int n,m;
       int flag = 0;
       scanf("%d%d",&n,&m);
       for(int i=1;i<=n;i++)
       {
           p[i].pre = i;
           p[i].relation = 1;
       }
       for(int i=0;i<m;i++)
       {
           int a,b;
           scanf("%d %d",&a,&b);
           if(find(a) == find(b))
           {
               if(p[a].relation == p[b].relation)
                   flag = 1;
           }
           else
               combine(a,b);
       }
       if(flag)
            printf("Scenario #%d:\nSuspicious bugs found!\n\n",ca++);
       else
           printf("Scenario #%d:\nNo suspicious bugs found!\n\n",ca++);
   }
}