Cod sursa(job #2569737)

Utilizator mitza23Mihai Grebla mitza23 Data 4 martie 2020 13:27:28
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.55 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <stack>

using namespace std;

ifstream fi("apm.in");
ofstream fo("apm.out");

struct muchie
{
    int v1, v2, c;
};

int n,m;
muchie e[400000];
int p[200001];
int c[200001];

int cmp(muchie a, muchie b)
{
    return a.c<b.c;
}

int parinte(int vf)
{
    while(p[vf]!=vf)
        vf=p[vf];
    return vf;
}

stack <pair<int,int> > s;

int main()
{
    fi>>n>>m;

    for(int i=1;i<=n;i++)
    {
        p[i]=i;
        c[i]=1;
    }

    for(int i=0;i<m;i++)
    {
        fi>>e[i].v1>>e[i].v2>>e[i].c;
    }

    sort(e,e+m,cmp);

    int nrm=1;
    int rez=e[0].c;

    p[e[0].v2]=e[0].v1;
    c[e[0].v2]=2;

    s.push({e[0].v1,e[0].v2});

    int p1,p2;
    for(int i=1;i<m;i++)
    {
        if(nrm<n)
        {
            p1=parinte(e[i].v1);
            p2=parinte(e[i].v2);

            if(p1!=p2)
            {
                rez+=e[i].c;
                s.push({e[i].v1,e[i].v2});
                nrm++;

                if(c[p1]>c[p2])
                {
                    c[p1]+=c[p2];
                    p[p2]=p1;
                }
                else
                {
                    c[p2]+=c[p1];
                    p[p1]=p2;
                }
            }
        }
        else
            break;
    }

    fo<<rez<<'\n'<<n-1<<'\n';
    while(!s.empty())
    {
        fo<<s.top().first<<" "<<s.top().second<<'\n';
        s.pop();
    }

    fi.close();
    fo.close();
    return 0;
}