Cod sursa(job #1344703)

Utilizator SagunistuStrimbu Alexandru Sagunistu Data 16 februarie 2015 22:19:02
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
#define nmax 200005
#include <algorithm>

using namespace std;

pair <int,pair<int,int> >p[2*nmax];
vector<pair<int,int> >v;
int n,m,t[nmax],s;

ifstream fin("apm.in");
ofstream fout("apm.out");

void citire()
{
    int x,y,c;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        p[i]=make_pair(c,make_pair(x,y));
    }
    for(int i=1;i<=n;i++)
        t[i]=i;
}

void grupare(int x,int y)
{
    t[t[x]]=t[y];
    v.push_back(make_pair(x,y));
}

int tata(int k)
{
    if(t[k]==k)
        return k;
    t[k]=tata(t[k]);
    return t[k];
}

void kruskal()
{
    int x,y,k;
    for(int i=1;i<=m;i++)
    {
        x=p[i].second.first;
        y=p[i].second.second;
        k=p[i].first;
        if(tata(x)!=tata(y))
            grupare(x,y),s+=k;
    }
}

void afisare()
{
    fout<<s<<"\n"<<v.size()<<"\n";
    for(vector<pair<int,int> >::iterator ii=v.begin();ii!=v.end();++ii)
        fout<<ii->first<<" "<<ii->second<<"\n";
}

int main()
{
    citire();
    sort(p+1,p+m+1);
    kruskal();
    afisare();
    return 0;
}