Cod sursa(job #2043162)

Utilizator proflaurianPanaete Adrian proflaurian Data 19 octombrie 2017 18:08:17
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include<bits/stdc++.h>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
const int N = 200010;
vector<tuple<int,int,int>> e;
vector<pair<int,int>> sol;
int n,m,c,x,y,j,cost,rx,ry,i,t[N],get_root(int);
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
        t[i]=i;
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>c;
        e.push_back(make_tuple(c,x,y));
    }
    sort(e.begin(),e.end());
    for(i=0,j=n-1;i<m&&j>0;i++)
    {
        tie(c,x,y)=e[i];
        rx=get_root(x);
        ry=get_root(y);
        if(rx!=ry)
        {
            cost+=c;
            sol.push_back(make_pair(x,y));
            j--;
            t[rx]=ry;
        }
    }
    g<<cost<<'\n'<<n-1<<'\n';
    for(auto it:sol)
        g<<it.first<<' '<<it.second<<'\n';
    return 0;
}
int get_root(int a)
{
    if(t[a]==a)return a;
    t[a]=get_root(t[a]);
    return t[a];
}