Cod sursa(job #1742353)

Utilizator c0mradec0mrade c0mrade Data 16 august 2016 12:48:20
Problema Arbore partial de cost minim Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include<bits/stdc++.h>
#define N 200001
using namespace std;
ifstream in("apm.in");
ofstream out("apm.out");
int n, m, ans, GR[N], t, sol[N];
struct edge{int x,y,c;}a[N];
int group(int i)
{
    if (GR[i] == i) return i;
    GR[i] = group(GR[i]);
    return GR[i];
}
void unity(int i,int j)
{
    GR[group(i)]=group(j);
}
int cmp(edge x,edge y)
{
    return x.c<y.c;
}

int main()
{
    in>>n>>m;
    for(int i=0;i<m;++i)
        in>>a[i].x>>a[i].y>>a[i].c;
    sort(a+1, a+m+1, cmp);
    for(int i=1;i<=n;++i)
        GR[i]=i;
    for(int i=0;i<m;++i)
    {
        if(group(a[i].x)!=group(a[i].y))
        {
            ans+=a[i].c;
            unity(a[i].x,a[i].y);
            sol[++t]=i;
        }
    }
    out<<ans<<'\n'<<n-1<<'\n';
    for(int i=1;i<n;++i)
        out<<a[sol[i]].x<<' '<<a[sol[i]].y<<'\n';
    return 0;
}