hdu1829向量法

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#define MAX 100002

using namespace std;

int father[MAX],rank[MAX];

void init(int n)
{
    for(int i = 1; i <=n; i ++)
        father[i] = i;
    memset(rank,0,sizeof(rank));
}

int find(int x)
{
    if(x!=father[x])
    {
        int temp = father[x];
        father[x] = find(father[x]);
        rank[x] = (rank[x] + rank[temp])%2;
    }
    return father[x];
}

int Union(int x,int y)
{
    int a = find(x);
    int b = find(y);
    if(a == b) return 1;
    father[a] = b;
    rank[a] = (rank[y]+1-rank[x])%2; //向量关系式根指向

    return 0;
}

int main()
{
    int a,b,m,n,stu,ans;
    scanf("%d",&n);

        for(int i = 1; i <=n; i ++)
        {
            cin>>stu>>m;
            init(stu);
            ans = 0;
            for(int j = 1; j <=m; j++)
            {
                scanf("%d %d",&a,&b);
                if(find(a)==find(b))
                {
                    if(rank[a]==rank[b])
                        ans = 1;
                }
                else
                    Union(a,b);
            }
            if(ans == 1)
                printf("Scenario #%d:\nSuspicious bugs found!\n\n",i);
            else
                printf("Scenario #%d:\nNo suspicious bugs found!\n\n",i);
        }

    return 0;
}