Cod sursa(job #2940368)

Utilizator mirceaspPetcu Mircea mirceasp Data 15 noiembrie 2022 13:12:43
Problema Arbore partial de cost minim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.57 kb
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#include <fstream>
#include <bits/stdc++.h>
using namespace std;
ifstream f("apm.in");
ofstream g("apm.out");
#define MAXN 100001
#define infinite 1e9
struct hashFunction
{
    size_t operator()(const pair<int ,
            int> &x) const
    {
        return x.first ^ x.second;
    }
};
int main()
{
    int n,m,cost,x,y;
    f>>n>>m;
    vector<vector<pair<int,int>>>lista;
    for(int i = 0;i<n+1;i++)
        lista.push_back({});
    for(int i = 0;i<m;i++)
    {
        f>>x>>y>>cost;
        lista[x].push_back({y, cost});
        lista[y].push_back({x,cost});
    }
    vector<int> distante(n+1,infinite);
    priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;
    int nrMuchii = 0;
    pq.push({0,1});
    vector<bool> inArbore(n+1,false);
    inArbore[1] = true;
    int costTotal = 0;
    vector<pair<int,int>> muchii;
    unordered_set<pair<int, int>,
            hashFunction> muchiiHash;
    distante[1] =0;
    vector<int>tata(n+1,0);
    int nodCurent;
    while (!pq.empty())
    {
        nodCurent = pq.top().second;
        int costNodCurent = pq.top().first;
        pq.pop();
        for(int j = 0;j<lista[nodCurent].size();j++)
            if(inArbore[lista[nodCurent][j].first] == false  && distante[lista[nodCurent][j].first]>lista[nodCurent][j].second)
            {
                distante[lista[nodCurent][j].first] = lista[nodCurent][j].second;
                tata[lista[nodCurent][j].first] = nodCurent;
                pq.push({ distante[lista[nodCurent][j].first],lista[nodCurent][j].first});

            }
        inArbore[nodCurent] = true;
        if(nodCurent!= 1) {
            int ok = 1;
//           for(auto muchie:muchii)
//               if(muchie.first == nodCurent && muchie.second == tata[nodCurent])
//                   ok = 0;
//           if(ok == 1) {
//               nrMuchii++;
//               muchii.push_back({nodCurent, tata[nodCurent]});
//           }
            if(muchiiHash.find({nodCurent,tata[nodCurent]}) == muchiiHash.end())
            {
                nrMuchii++;
               muchii.push_back({nodCurent, tata[nodCurent]});
                muchiiHash.insert({nodCurent, tata[nodCurent]});
            }

        }
    }
    for(int i = 1;i<distante.size();i++)
        costTotal += distante[i];
    g<<costTotal<<endl;
    g<<nrMuchii<<endl;
    for(auto muchie:muchii)
        g<<muchie.first<<' '<<muchie.second<<endl;
    f.close();g.close();

}