Cod sursa(job #2630210)

Utilizator iulianarsenoiuArsenoiu Iulian iulianarsenoiu Data 24 iunie 2020 17:45:44
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <bits/stdc++.h>

using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
vector<pair<int,pair<int,int>>> e;
vector <pair<int,int>> rez;
int n,m,cost,t[200005],rang[200005];
int reprezentant(int x)
{
    if(t[x]!=x)
    {
        return reprezentant(t[x]);
    }
    return t[x];
}
bool uneste(int x, int y)
{
    x=reprezentant(x);
    y=reprezentant(y);
    if(x==y)
    {
        return false;
    }
    if(rang[x]>rang[y])
    {
        t[y]=x;
        rang[x]+=rang[y];
        rang[y]=0;
        return true;
    }
    t[x]=y;
    rang[y]+=rang[x];
    rang[x]=0;
    return true;
}
void apm()
{
    for(auto it : e)
    {
        int x=it.second.first;
        int y=it.second.second;
        if(t[x]!=t[y])
        {
            if(uneste(x,y))
            {
                cost+=it.first;
                rez.push_back(it.second);
            }
        }
    }
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        e.push_back({c,{x,y}});
    }
    sort(e.begin(),e.end());
    for(int i=1;i<=n;i++)
    {
        t[i]=i;
        rang[i]=1;
    }
    apm();
    g<<cost<<'\n'<<rez.size()<<'\n';
    for(auto it : rez)
    {
        g<<it.first<<' '<<it.second<<'\n';
    }
    return 0;
}