Cod sursa(job #3370531)

Utilizator Dimix12Miron Dimitrie Dimix12 Data 26 octombrie 2026 14:50:35
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <bits/stdc++.h>
#include <fstream>
using namespace std;

const int NMAX = 2e5;
int p[NMAX + 1], sz[NMAX + 1];

ifstream f("apm.in");
ofstream g("apm.out");

int Find(int x) {
    while (x != p[x]) {
        x = p[x];
    }
    return x;
}

void Union(int x, int y) {
    x = Find(x);
    y = Find(y);
    if (sz[x] > sz[y]) {
        p[y] = x;
        sz[x] += sz[y];
    } else {
        p[x] = y;
        sz[y] += sz[x];
    }
}

struct muchie {
    int x, y, cost;
};

muchie v[400001], r[400001];

bool cmp(muchie a, muchie b) {
    return a.cost < b.cost;
}

int main() {
    int n, m;
    f >> n >> m;
    for (int i = 1; i <= n; i++) {
        p[i] = i;
        sz[i] = 1;
    }
    for (int i = 1; i <= m; i++) {
        f >> v[i].x >> v[i].y >> v[i].cost;
    }
    sort(v+1, v+m+1, cmp);
    int sum = 0;
    int nr = 0;
    for (int i = 1; i <= m; i++) {
        if (Find(v[i].x) != Find(v[i].y)) {
            nr++;
            r[nr] = v[i];
            sum += v[i].cost;
            Union(v[i].x, v[i].y);
        }
    }
    // afisati nr de muchii si muchiile din apm - muchiile din vectorul r
    g << sum << '\n' << nr << '\n';
    for (int i = 1; i <= nr; i ++)
        g << r[i].x << ' ' << r[i].y << '\n';
    
    g.close();
    return 0;
}