Cod sursa(job #1693106)

Utilizator msschFMI - Enache Alexandru Madalin mssch Data 22 aprilie 2016 13:48:33
Problema Arbore partial de cost minim Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 2.24 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, int> s1, pair <int, int> s2)
   {
       return s1.first > s2.first;
   }
};

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

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

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

    for(i = 0; i < v[1].size(); i++)
    {
        vec.push_back(make_pair(v[1][i].second, v[1][i].first));
        p[v[1][i].first] = 1;
    }
    for(int i = 2; i <= n; i++)
    {
        viz[i] = 0;

        if(p[i] != 1)
        {
            vec.push_back(make_pair(1005, i));
        }
    }
    viz[1] = 1;

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

    while(!vec.empty())
    {
        x = vec[0].second;
        s += vec[0].first;
        pop_heap (vec.begin(), vec.end(), Comp());
        vec.pop_back();
        sol.push_back(make_pair(x, p[x]));
        viz[x] = 1;

        for(i = 0; i < v[x].size(); i++)
        {
            if(viz[v[x][i].first] == 0)
            {
                for(j = 0; j < vec.size(); j++)
                {
                    if(vec[j].second == v[x][i].first)
                    {
                        if(v[x][i].second < vec[j].first)
                        {
                            vec.erase(vec.begin() + j);
                            vec.push_back(make_pair(v[x][i].second, v[x][i].first));
                            push_heap (vec.begin(), vec.end(), Comp());
                            p[v[x][i].first] = x;
                        }
                    }
                }
            }
        }
    }

    fout << s << endl;
    fout << sol.size() << endl;

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

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