Cod sursa(job #2572030)

Utilizator dimi999Dimitriu Andrei dimi999 Data 5 martie 2020 11:18:17
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <bits/stdc++.h>
using namespace std;

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

struct elem
{
    int dest, node, cost;
}v[400005];

int dads[200005];
int rnk[200005];

int cost, k;

int sol[200005][2];

 int n, m;


inline bool cmp(const elem &a, const elem &b)
{
    return a.cost < b.cost;
}

int root(int node)
{
    int father = dads[node];

    while(father != dads[father])
        father = dads[father];

    dads[node] = father;
    return father;
}

void join(int p, int q)
{
    p = root(p);
    q = root(q);

    if(rnk[p] < rnk[q])
        dads[p] = q;
    else
        if(rnk[p] > rnk[q])
            dads[q] = p;
    else
        rnk[q]++, dads[p] = q;
}

void kruskal()
{
    for(int i = 1; i <= m; i++)
        if(root(v[i].node) != root(v[i].dest))
            {
                join(v[i].node,v[i].dest);
                cost += v[i].cost;
                sol[++k][0] = v[i].node;
                sol[k][1] = v[i].dest;
            }
    fout << cost << '\n';
    fout << k << '\n';
    for(int i = 1; i <= k; i++)
        fout << sol[i][0] << " " << sol[i][1] << '\n';
}

int main()
{
    fin >> n >> m;

    for(int i = 1; i <= m; i ++)
    {
        int x, y, z;

        fin >> x >> y >> z;

        v[i] = {x,y,z};
    }

    for(int i = 1; i <= n; i++)
        dads[i] = i;

    sort(v + 1,v + m + 1,cmp);

    kruskal();
    return 0;
}