Cod sursa(job #2526017)

Utilizator AlexandruBrezuleanuAlexandruBrezuleanu AlexandruBrezuleanu Data 18 ianuarie 2020 10:38:58
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.6 kb
#include <bits/stdc++.h>
#define NMAX 200002

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

struct muchie
{
    int x, y;
    int cost;
    friend bool operator >(muchie, muchie);
};

bool operator> (muchie a, muchie b)
{
    return a.cost>b.cost;
}

priority_queue<muchie, vector<muchie>, greater<muchie> > H;

int n;
int tata[NMAX];
int h[NMAX];
int costmin;
muchie sel[NMAX];

int Find(int x);
void Union(int x, int y);
void citire();
void kruskal();
void afisare();

int main()
{
    citire();
    kruskal();
    afisare();
    return 0;
}

int Find(int x)
{
    int rad, y;
    rad=x;
    while (tata[rad]) rad=tata[rad];
    while (tata[x])
    {
        y=tata[x];
        tata[x]=rad;
        x=y;
    }
    return rad;
}

void Union(int x, int y)
{
    int rx, ry;
    rx=Find(x);
    ry=Find(y);
    if (h[rx]>h[ry])
        tata[ry]=rx;
    else
    {
        tata[rx]=ry;
        if (h[rx]==h[ry]) h[ry]++;
    }
}

void citire()
{
    muchie a;
    int i, m;
    fin>>n>>m;
    for (i=0; i<m; i++)
    {
        fin>>a.x>>a.y>>a.cost;
        H.push(a);
    }
}

void kruskal()
{
    muchie a;
    int nrsel=0, c1, c2;
    while (nrsel<n-1)
    {
        a=H.top();
        H.pop();
        c1=Find(a.x);
        c2=Find(a.y);
        if (c1!=c2)
        {
            sel[nrsel++]=a;
            costmin+=a.cost;
            Union(c1, c2);
        }
    }
}

void afisare()
{
    int i;
    fout<<costmin<<'\n'<<n-1<<'\n';
    for (i=0; i<n-1; i++)
        fout<<sel[i].x<<' '<<sel[i].y<<'\n';
}