#include <iostream>
#include <fstream>
using namespace std;
int a[100][100],tata[10000],oo=100000,n;
bool viz[10000];

ifstream in("graf.txt");

void Prim(int nod_start)
{int i,j,p,min,k;

viz[nod_start]=1; //marcam nodul de start vizitat
for(i=1;i<=n;i++)
tata[i]=nod_start;
tata[nod_start]=0;// initializam vectorul de tati

for(k=1;k<=n-1;k++)
{min=oo; //minimul este initializat cu infinit
p=0;
for(i=1;i<=n;i++)
{if(!viz[i] && a[i][tata[i]]<min) //cautam un nod nevizitat si il comparam cu minimul
{min=a[i][tata[i]];
p=i;//retinem nodul in variabila p
}
viz[p]=1; //il marcam vizitat la sfarsit
}

for(i=1;i<=n;i++)
if(!viz[i] && a[i][tata[i]]>a[i][p])
tata[i]=p;
}
cout<<"Arborele de cost minim este: "<<endl;
for(int i=1;i<=n;i++)
{
    cout<<tata[i]<<" "<<i<<" "<< a[i][tata[i]]<<endl;
}
//cout<<c<<endl;
}
int main()
{ int i,j,C,x;
    in>>n;
    for(int i=1;i<=n;i++)
    for(int j=1;j<=n;j++)
        if(i!=j) a[i][j]=a[j][i]=oo;
    while(in>>i>>j>>C)
        a[i][j]=a[j][i]=C;
        cout<<"Nod de start = ";
        cin>>x;
    Prim(x);
}