Cod sursa(job #3344043)

Utilizator liadariaLia Daria Ostafi liadaria Data 1 martie 2026 11:01:06
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <fstream>
#define NMAX 200001
#define MMAX 400001
#include <queue>
using namespace std;
ifstream fin("apm.in");
ofstream fout("apm.out");
struct muchie
{
    int x,y,c;
    friend bool operator < (muchie a,muchie b);
};
int n,m,cmin;
int rg[NMAX],tata[NMAX];
muchie apm[MMAX];
priority_queue<muchie>H;
bool operator < (muchie a,muchie b)
{
    return a.c>b.c;
}
void kruskal();
int gaseste(int x);
void uneste(int x,int y);
int main()
{
    int i;
    muchie M;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>M.x>>M.y>>M.c;
        H.push(M);
    }
    kruskal();
    fout<<cmin<<'\n'<<n-1<<'\n';
    for(i=1;i<n;i++) fout<<apm[i].x<<' '<<apm[i].y<<'\n';
    return 0;
}
void kruskal()
{
    int nrsel=0,rx,ry;
    muchie m;
    while(nrsel<n-1)
    {
        m=H.top(); H.pop();
        rx=gaseste(m.x); ry=gaseste(m.y);
        if(rx!=ry)
        {
            //le unim
            cmin+=m.c;
            apm[++nrsel]=m;
            uneste(rx,ry);
        }
    }
}
int gaseste(int x)
{
    int y,rx;
    for(rx=x;tata[rx];rx=tata[rx]);
    while(tata[x] && tata[x]!=rx)
    {
        y=tata[x];
        tata[x]=rx;
        x=y;
    }
    return rx;
}
void uneste(int x,int y)
{
    if(rg[x]>rg[y]) tata[y]=x;
    else if(rg[y]>rg[x]) tata[x]=y;
    else
    {
        tata[y]=x;
        rg[x]++;
    }
}