Cod sursa(job #3254176)

Utilizator ArthurrrfubinacaARthur Paun Arthurrrfubinaca Data 6 noiembrie 2024 13:35:10
Problema Arbore partial de cost minim Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream>
#include <queue>
#include <fstream>
#include <vector>
#define Nmax 100000

using namespace std;

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

vector<pair<int,int>> g[Nmax];
int TT[Nmax];
int d[Nmax];
bool viz[Nmax];
int sum,n,m,x,y,c;

void prim(int start)
{
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
    pq.push(make_pair(0,start));
    while(!pq.empty())
    {
        int nod=pq.top().second;
        pq.pop();
        if(!viz[nod])
        {
            for(auto i : g[nod])
            {
                if(d[i.second]>i.first && !viz[i.second])
                {
                    d[i.second]=i.first;
                    TT[i.second]=nod;
                    pq.push(make_pair(i.first,i.second));
                }
            }
        }
        viz[nod]=true;
    }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>c;
        g[x].push_back(make_pair(c,y));
        g[y].push_back(make_pair(c,x));
    }
    for(int i=2;i<=n;i++)
        d[i]=INT_MAX;
    prim(1);
    for(int i=2;i<=n;i++)
        sum+=d[i];
    fout<<sum<<'\n';
    fout<<n-1<<'\n';
    for(int i=2;i<=n;i++)
        fout<<i<< " " <<TT[i]<< '\n';
    return 0;
}