여러가지 종교 더블릿

#include <stdio.h>
#include <algorithm>
 
using namespace std;
 
int root[200000] = { 0 };
 
int find(int x) {
    if (root[x] == x)
        return x;
    else 
        return root[x] = find(root[x]);
}
 
void unify(int a, int b) {    
    a = find(a);
    b = find(b);
 
    if (a > b)
        swap(a, b);
 
    root[b] = a;
}
 
int main() {
    int n, m;
    scanf("%d %d", &n, &m);
 
    for (int i = 1; i <= n; i++) {
        root[i] = i;
    }
 
    for (int i = 0; i < m; i++) {
        int a, b;
        scanf("%d %d", &a, &b);
        unify(a, b);
    }
 
    int rst = 0;
    for (int i = 1; i <= n; i++) {        
        if (root[i] == i)
            rst++;
    }
    
    printf("%d",rst);
}