10583 Ubiquitous Religions

#include <iostream>
#include <set>
using namespace std;

const int MAXN = 50005;
int p[MAXN];

int find(int u){
    if (p[u] == u) return u;
    return  p[u] = find(p[u]);
}

void link(int u, int v){
    int a = find(u), b = find(v);
    if (a != b){
	p[a] = b;
    }
}

int main(){
    int n, m, C = 1;
    while (scanf("%d %d", &n, &m) == 2){
	if (n == 0 and m == 0) break;
	for (int i = 0; i < n; ++i) p[i] = i;
	for (int i = 0; i < m; ++i){
	    int u, v;
	    scanf("%d %d", &u, &v);
	    u--, v--;
	    link(u, v);
	}
	set<int> ans;
	for (int i = 0; i < n; ++i) ans.insert(find(i));
	printf("Case %d: %d\n", C++, ans.size());
    }
    return 0;
}

gistfile2.hpp

#include <iostream>
#include <set>
using namespace std;

const int MAXN = 50005;
int p[MAXN];

int find(int u){
    if (p[u] == u) return u;
    return  p[u] = find(p[u]);
}

void link(int u, int v){
    int a = find(u), b = find(v);
    if (a != b){
	p[a] = b;
    }
}

int main(){
    int n, m, C = 1;
    while (scanf("%d %d", &n, &m) == 2){
	if (n == 0 and m == 0) break;
	for (int i = 0; i < n; ++i) p[i] = i;
	for (int i = 0; i < m; ++i){
	    int u, v;
	    scanf("%d %d", &u, &v);
	    u--, v--;
	    link(u, v);
	}
	set<int> ans;
	for (int i = 0; i < n; ++i) ans.insert(find(i));
	printf("Case %d: %d\n", C++, ans.size());
    }
    return 0;
}