Cod sursa(job #1426554)

Utilizator alex.vasiuVasiu Alexandru alex.vasiu Data 29 aprilie 2015 21:54:53
Problema Arbore partial de cost minim Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
const int INF = 1<<19;
int a[1500][1500],c, n, m, t[1500],cost[1500];
bool viz[1501];
void citire()
{
    fin>>n>>m;
    int x,y,c,i;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y>>c;
        a[x][y]=c;
        a[y][x]=c;
    }
    fin.close();
}
void apm()
{
    for(int 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++)
    {
        int mn=INF,pz=-1;
        for(int i=1; i<=n; i++)
            if(viz[i]==0 && cost[i]<mn)
            {
                mn=cost[i];
                pz=i;
            }
            c+=mn;
        viz[pz]=1;
        for(int 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(int i=2; i<=n; i++)
        if(a[t[i]][i])
            fout<<t[i]<<" "<<i<<"\n";
}
int main()
{
    citire();
    apm();
    afisare();
}