Cod sursa(job #2693972)

Utilizator Harsa_AndreiHarsa Andrei Harsa_Andrei Data 7 ianuarie 2021 18:59:24
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 kb
#include<stdio.h>
#include<algorithm>
#include<fstream>

using namespace std;
#define N 200010
#define M 400010

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

struct edges
{
    int x,y;
    short int c;
};



int n,m;
edges v[M];
int ind[M],t[N],gr[N];
int cost,rez[N];

void read()
{
    fin>>n>>m;
    for(int i=0; i<m; ++i)
    {   fin>>v[i].x>>v[i].y>>v[i].c;
        ind[i]=i;
    }
}

int find(int x)
{
    int r=x;
    for(; t[r]!=r; r=t[r])
        ;
    while(t[x]!=x)
    {
        int aux=t[x];
        t[x]=r;
        x=aux;
    }
    return r;
}

void reuniune(int x,int y)
{
    if(gr[x]<gr[y])
        t[x]=y;
    else
        t[y]=x;
    if(gr[x]==gr[y])
        ++gr[x];
}

bool compar(const int &x,const int &y)
{
    return (v[x].c<v[y].c);
}

void solve()
{
    for(int i=1; i<=n; ++i)
    {
        t[i]=i;
        gr[i]=1;
    }

    sort(ind,ind+m,compar);
    int n1=n-1;

    for(int i=0; i<m && rez[0]!=n1; ++i)
    {
        int nod=ind[i];
        if(find(v[nod].x)!=find(v[nod].y))
        {
            cost+=v[nod].c;
            rez[++rez[0]]=nod;
            reuniune(find(v[nod].x),find(v[nod].y));
        }
    }
}

void print()
{
    fout<<cost<<endl<<n-1<<endl;
    for(int i=1; i<=rez[0]; ++i)
        fout<<v[rez[i]].x<<" "<<v[rez[i]].y<<endl;

}

int main()
{

    read();
    solve();
    print();
    fin.close();
    fout.close();
    return 0;
}