Cod sursa(job #2738246)

Utilizator gabiadiBoscanici Adrian Gabriel gabiadi Data 5 aprilie 2021 16:55:04
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <iostream>
#include <fstream>
#include <algorithm>

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

const int NMAX=200000;
const int MMAX=400000;
struct muchie
{
    int i,j,c;
};

int n,m,cost;

muchie M[MMAX+1];
int CC[NMAX+1];
int NrM[NMAX];

void citire()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
        f>>M[i].i>>M[i].j>>M[i].c;
}

void afis()
{
    g<<cost<<'\n';
    g<<n-1<<'\n';
    for(int i=1;i<n;i++)
    {
        int k=NrM[i];
        g<<M[k].i<<' '<<M[k].j<<'\n';
    }

}

int comp(const muchie &a ,const muchie &b)
{
    /**if(a.c<=b.c)return 1;
        else return 0;*/
    return a.c < b.c;
}

int Find(int i)
{
    if(CC[i]==0)
        return i;
    return CC[i]=Find(CC[i]);
}

void Kruskal()
{
    sort(M+1,M+m+1,comp);///[1,m+1]
    int nm=0;
    for(int i=1;i<=m;i++)
    {
        int ci=Find(M[i].i),cj=Find(M[i].j);
        if(ci!=cj)
        {
            cost+=M[i].c;
            CC[ci]=cj;
            NrM[++nm]=i;
            if(nm==n-1)
                break;
        }
    }
}


int main()
{
    citire();
    Kruskal();
    afis();
    return 0;
}