Cod sursa(job #2674900)

Utilizator cristina_borzaCristina Borza cristina_borza Data 20 noiembrie 2020 17:45:20
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.5 kb
#include <bits/stdc++.h>

using namespace std;

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

const int Dim = 4e5 + 5;

struct edge {
    int x, y, cost;
    bool operator <(const edge &other) {
        return cost < other.cost;
    }
};

int n, m, costTotal;
int tata[Dim], w[Dim];

edge e[Dim];

vector <pair<int, int> > ans;

int findTata(int node) {
    int cn = node;
    while(tata[cn] != cn) {
        cn = tata[cn];
    }

    while(node != cn) {
        int aux = node;
        tata[node] = cn;
        node = tata[aux];
    }
    return node;
}

void uneste(int node1, int node2) {
    int tNode1 = findTata(node1);
    int tNode2 = findTata(node2);
    if(w[tNode1] < w[tNode2]) {
        tata[tNode1] = tNode2;
        w[tNode2] += w[tNode1];
    } else {
        tata[tNode2] = tNode1;
        w[tNode1] += w[tNode2];
    }
}

int main() {
    f >> n >> m;
    for(int i = 1; i <= m; ++i) {
        f >> e[i].x >> e[i].y >> e[i].cost;
    }

    sort(e + 1, e + m + 1);
    for(int i = 1; i <= n; ++i) {
        w[i] = 1;
        tata[i] = i;
    }

    for(int i = 1; i <= m; ++i) {
        if(findTata(e[i].x) != findTata(e[i].y)) {
            uneste(e[i].x, e[i].y);
            ans.push_back({e[i].x, e[i].y});
            costTotal += e[i].cost;
        }
    }

    g << costTotal << '\n' << n - 1 << '\n';
    for(auto it = ans.begin(); it != ans.end(); ++it) {
        g << it -> first << " " << it -> second << '\n';
    }
    return 0;
}