Cod sursa(job #2672691)

Utilizator CleliaClelia Maria Dobrescu Clelia Data 14 noiembrie 2020 14:07:26
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.35 kb
#include <fstream>
#include <vector>
#include <set>
using namespace std;
ifstream fin ("apm.in");
ofstream fout ("apm.out");
struct ura1
{
    int nod,cost;
    bool operator <(const ura1 &other)const
    {
        return cost<other.cost;
    };
};
struct ura2
{
    int x,y;
};
vector <ura1> l[200005];
multiset <ura1> s;
ura2 sol[200005];
int v[200005],cor[200005],vc[200005];
void apm (int x)
{
    int i,y,c;
    for (i=0;i<l[x].size();i++)
    {
        y=l[x][i].nod;
        c=l[x][i].cost;
        if (v[y]>c)
        {
            v[y]=c;
            s.insert(l[x][i]);
            cor[y]=x;
        }
    }
}
int main ()
{
    int rez=0,n,m,i,x,y,c,nod;
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        l[x].push_back({y,c});
        l[y].push_back({x,c});
    }
    for (i=2;i<=n;i++)
    {
        v[i]=2000000000;
        s.insert({i,v[i]});
    }
    apm(1);
    vc[1]=1;
    for (i=1;i<n;i++)
    {
        nod=s.begin()->nod;
        while (vc[nod])
        {
            s.erase(s.begin());
            nod=s.begin()->nod;
        }
        s.erase(s.begin());
        vc[nod]=1;
        apm(nod);
        rez+=v[nod];
        sol[i]={nod,cor[nod]};
    }
    fout<<rez<<'\n'<<n-1<<'\n';
    for (i=1;i<n;i++)
        fout<<sol[i].x<<" "<<sol[i].y<<'\n';
    return 0;
}