Cod sursa(job #2576782)

Utilizator maria15Maria Dinca maria15 Data 6 martie 2020 22:44:52
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.36 kb
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

ifstream fin("apm.in");
ofstream fout("apm.out");

int n, m, i, a, b, c, t[200004];
pair<int, pair<int, int> > edge[400002];
vector<pair<int, int> > sol;

int rad(int nod){
    while(t[nod] > 0)
        nod = t[nod];
    return nod;
}

int main(){
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>a>>b>>c;
        edge[i] = {c, {a, b}};
    }
    sort(edge+1, edge+m+1);
    for(i=1;i<=n;i++)
        t[i] = -1;
    pair<int, int> muchie = edge[1].second;
    sol.push_back(muchie);
    t[muchie.first]--;
    t[muchie.second] = muchie.first;
    int ind = 2;
    int cost = edge[1].first;
    while(sol.size() < n-1){
        muchie = edge[ind].second;
        a = muchie.first;
        b = muchie.second;
        int rad1 = rad(a);
        int rad2 = rad(b);
        if(rad1 != rad2){
            sol.push_back(muchie);
            cost += edge[ind].first;
            if(t[rad1] < t[rad2]){
                t[rad1] += t[rad2];
                t[rad2] = rad1;
            }
            else{
                t[rad2] += t[rad1];
                t[rad1] = rad2;
            }
        }
        ind++;
    }
    fout<<cost<<"\n"<<sol.size()<<"\n";
    for(i=0;i<sol.size();i++)
        fout<<sol[i].first<<" "<<sol[i].second<<"\n";
    return 0;
}