Cod sursa(job #2667826)

Utilizator kerry6205Motiu Radu kerry6205 Data 3 noiembrie 2020 21:42:43
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <cstring>
#define NMAX 200005
#define MMAX 400005
using namespace std;

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

struct muchie
{
    int x, y;
    short c;
}m[MMAX];

int N, M, cost, ct;
int tata[NMAX], id[NMAX];

bool comp(muchie a, muchie b)
{
    return a.c < b.c;
}

void citire()
{
    in >> N >> M;
    for(int i = 1; i <= M; i++)
        in >> m[i].x >> m[i].y >> m[i].c;

    sort(m + 1, m + M + 1, comp);
}

int gasire(int x)
{
    if(tata[x] != x)
        tata[x]  = gasire(tata[x]);
    return tata[x];
}

void unire(int a, int b)
{
    if(a != b)
        if(a < b)
            tata[b] = a;
        else
            tata[a] = b;
}

void kruskal()
{
    for(int i = 1; i <= M; i++)
    {
        int a = gasire(m[i].x);
        int b = gasire(m[i].y);
        if(a != b)
        {
            unire(a, b);
            cost += m[i].c;
            id[++ct] = i;
        }
    }
}

int main()
{
    citire();
    for(int i = 1; i <= N; i++)
        tata[i] = i;

    kruskal();

    out << cost << '\n' << ct << '\n';
    for(int i = 1; i <= N - 1; i++)
        out << m[id[i]].x << ' ' <<  m[id[i]].y << '\n';
}