POJ 2524 Ubiquitous Religions - (并查集)

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/rsy56640/article/details/80034962

题目链接：http://poj.org/problem?id=2524

#include <stdio.h>  
#include <vector>   
#include <algorithm>
using namespace std;

//POJ 2524 Ubiquitous Religions

inline int getFather(int *p, int x)
{
    if (p[x] == x)return x;
    p[x] = getFather(p, p[x]);
    return p[x];
}

inline void un(int *p, int x, int y)
{
    int fx = getFather(p, x);
    int fy = getFather(p, y);
    p[fx] = fy;
}

inline bool judge(int *p, int x, int y)
{
    return getFather(p, x) == getFather(p, y);
}

int main()
{
    int count = 0;
    int n, m;
    while (~scanf("%d%d", &n, &m))
    {
        count++;
        if (n == 0)break;
        int *p = new int[n];
        for (int i = 0; i < n; ++i)
            p[i] = i;
        int A, B;
        for (int i = 0; i < m; ++i)
        {
            scanf("%d%d", &A, &B);
            A--; B--;
            un(p, A, B);
        }
        vector<int> diff_religion;
        for (int i = 0; i < n; ++i)
            diff_religion.push_back(getFather(p, i));
        std::sort(diff_religion.begin(), diff_religion.end());
        vector<int>::iterator it = std::unique(diff_religion.begin(), diff_religion.end());
        printf("Case %d: %d\n", count, it - diff_religion.begin());
    }
    system("pause");
    return 0;
}