Cod sursa(job #1693195)

Utilizator msschFMI - Enache Alexandru Madalin mssch Data 22 aprilie 2016 16:57:14
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2.09 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;

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

struct Comp
{
   bool operator()(pair <int, pair <int, int> > s1, pair <int, pair <int, int> > s2)
   {
       return s1.first > s2.first;
   }
};

int main()
{
    int n, m, x, y, c, s = 0;
    unsigned int i;

    vector <pair <int, int> > *v;

    fin >> n >> m;

    v = new vector <pair <int, int> >[n + 1];

    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y >> c;
        v[x].push_back(make_pair(y, c));
        v[y].push_back(make_pair(x, c));
    }

    int *d = new int [n + 1];
    int *viz = new int [n + 1];

    vector <pair <int, pair <int, int> > >vec;
    vector <pair <int, int> > sol;

    for(int i = 2; i <= n; i++)
    {
        viz[i] = 0;
        d[i] = 1005;
    }
    viz[1] = 1;

    for(i = 0; i < v[1].size(); i++)
    {
        vec.push_back(make_pair(v[1][i].second,make_pair(v[1][i].first, 1)));
        d[v[1][i].first] = v[1][i].second;
    }

    make_heap(vec.begin(), vec.end(), Comp());

    while(!vec.empty())
    {
        x = vec[0].second.first;
        y = vec[0].second.second;
        c = vec[0].first;
        pop_heap (vec.begin(), vec.end(), Comp());
        vec.pop_back();

        if(viz[x] == 0)
        {
            for(i = 0; i < v[x].size(); i++)
            {
                if(viz[v[x][i].first] == 0 && v[x][i].second < d[v[x][i].first])
                {
                    d[v[x][i].first] = v[x][i].second;
                    vec.push_back(make_pair(v[x][i].second, make_pair(v[x][i].first, x)));
                    push_heap (vec.begin(), vec.end(), Comp());
                }
            }
            s += c;
            sol.push_back(make_pair(x, y));
            viz[x] = 1;
        }
    }

    fout << s << "\n";
    fout << sol.size() << "\n";

    for(i = 0; i < sol.size(); i++)
    {
        fout << sol[i].first << " " << sol[i].second << "\n";
    }

    fin.close();
    fout.close();
    return 0;
}