Cod sursa(job #1428694)

Utilizator alex.vasiuVasiu Alexandru alex.vasiu Data 4 mai 2015 22:17:14
Problema Arbore partial de cost minim Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
const int64_t INF = 1<<21;
int64_t a[1100][1100],c=0, n, m, t[1100],cost[1100];
bool viz[1101];
void citire()
{
    fin>>n>>m;
    int64_t x,y,c1,i;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y>>c1;
        a[x][y]=c1;
        a[y][x]=c1;
    }
    fin.close();
}
void apm()
{
    for(int64_t i=2; i<=n; i++)
    {
        if(a[1][i])
            cost[i]=a[1][i];
        else
            cost[i]=INF;
            t[i]=1;
    }
    viz[1]=1;
    t[1]=0;
    for(int j=1; j<n; j++)
    {
        int64_t mn=INF,pz=-1;
        for(int64_t i=1; i<=n; i++)
            if(viz[i]==0 && cost[i]<mn)
            {
                mn=cost[i];
                pz=i;
            }
        c+=mn;
        viz[pz]=1;
        for(int64_t i=1; i<=n; i++)
            if(viz[i]==0 && a[pz][i]<cost[i] && a[pz][i])
            {
                t[i]=pz;
                cost[i]=a[pz][i];
            }
    }
}
void afisare()
{
    fout<<c<<"\n"<<n-1<<"\n";
    for(int64_t i=2; i<=n; i++)
        if(a[t[i]][i])
            fout<<t[i]<<" "<<i<<"\n";
}
int main()
{
    citire();
    apm();
    afisare();
}