[C++] HackerRank 해커랭크 Roads and Libraries

문제링크 : https://www.hackerrank.com/challenges/torque-and-development

#include <bits/stdc++.h>
using namespace std;
vector<int> p;
int f(int a) { return p[a] == a ? a : p[a] = f(p[a]); }
void u(int a, int b) { p[f(a)] = f(b); }
int main() {
    int T; cin >> T; while (T--) {
        int N, M, a, b;
        long long c, d;
        cin >> N >> M >> c >> d;
        p.clear(); p.resize(N);
        iota(p.begin(), p.end(), 0);
        while (M--) {
            cin >> a >> b;
            --a, --b;
            u(a, b);
        }
        int comp = 0;
        for (int i = 0; i<N; ++i) {
            if (p[i] == i)++comp;
        }
        cout << (comp*c + (N - comp)*min(c, d)) << "\n";
    }
 
    return 0;
}