TYVJ 1017 冗余关系 by C++

就机会复习一下并查集…

#include<iostream>
#include<string.h>
using namespace std;
const int maxn=1001;
int f[maxn];
int n,m,tot=0;

int find(int x)
{
    int i=x;
    while (f[i]!=0) i=f[i];
    return i;
}

int main()
{
    memset(f,0,sizeof(f));
    cin >> n >> m;
    int prex,prey,fx,fy;
    for (int i=0;i<n;i++){
        cin >> prex >> prey;
        fx=find(prex);
        fy=find(prey);
        fx==fy?tot++:f[fx]=fy;
    }
    cout << tot << endl;
    return 0;
}