Cod sursa(job #2697851)

Utilizator alexia208160Popescu Alexia Maria alexia208160 Data 20 ianuarie 2021 00:25:45
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.65 kb
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

const int MMAX = 400000;
const int NMAX = 200000;

struct Edge
{
    int x, y, z;
};

struct Parents
{
    int root, siz;
}p[NMAX + 4];

inline bool cmp(const Edge &a, const Edge &b)
{
    if(a.z == b.z)
        return a.x < b.x;
    return a.z < b.z;
}

vector <Edge>v;
Edge a[NMAX + 5];

struct Padure
{
    int Find(int x)
    {
        if(p[x].root == x)
            return x;
        p[x].root = Find(p[p[x].root].root);
        return p[x].root;
    }

    void Unite(int x, int y)
    {
        y = Find(y);
        x = Find(x);
        if(p[x].siz > p[y].siz)
            p[x].root = y;
        else if (p[x].siz < p[y].siz)
            p[y].root = x;
        else
        {
            p[x].root = y;
            p[x].siz++;
        }
    }

}Pad;

int main()
{
    int n, m;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y, z;
        fin >> x >> y >> z;
        v.push_back({x, y, z});
    }
    sort(v.begin(), v.end(), cmp);

    for(int i = 1; i <= n; i++)
    {
        p[i].root = i;
        p[i].siz = 1;
    }

    int r = 0;
    for(int i = 0; i < m; i++)
        if(Pad.Find(v[i].x) != Pad.Find(v[i].y))
        {
            Pad.Unite(v[i].x, v[i].y);
            a[++r] = v[i];
        }

    int cost = 0;

    for(int i = 1; i <= r; i++)
    {
        cost += a[i].z;
    }

    fout << cost << '\n' << r << '\n';

    for(int i = 1; i <= r; i++)
        fout << a[i].y << ' ' << a[i].x << '\n';
    return 0;
}