Cod sursa(job #2118389)

Utilizator puzzleFlutur Vasile puzzle Data 30 ianuarie 2018 16:53:08
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.74 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

ifstream in("dijkstra.in");
ofstream out("dijkstra.out");

const int Nmax = 50005;
const int oo = (1 << 30);

int N, M;
int D[Nmax]; //vector distante
bool inCoada[Nmax]; //spune daca un nod este vizitat sau nu

vector < pair < int, int > > G[Nmax];

struct comparaDistante //ajuta la stabilirea minimului
{
    bool operator()(int x, int y)
    {
        return D[x] > D[y];
    }
};
priority_queue < int, vector < int >, comparaDistante> Coada;

void Citeste()
{
    in >> N >> M;
    for(int i = 1; i <= M; i++)
    {
        int x, y, c;
        in >> x >> y >> c;
        G[x].push_back(make_pair(y,c));
    }
}
void Dijkstra (int nodStart)
{
    for(int i = 1; i <=N; i++)
        D[i] = oo;
    D[nodStart] = 0;
    Coada.push(nodStart);
    inCoada[nodStart] = true;
    while(!Coada.empty())
    {
        int nodCurent = Coada.top();
        Coada.pop();
        inCoada[nodCurent] = false;

        for(size_t i = 0; i < G[nodCurent].size(); i++)
        {
            int Vecin = G[nodCurent][i].first;
            int Cost = G[nodCurent][i].second;
            if(D[nodCurent] + Cost < D[Vecin])
            {
                D[Vecin] = D[nodCurent] + Cost;
                if(inCoada[Vecin] == false)
                {
                    Coada.push(Vecin);
                    inCoada[Vecin] = true;
                }
            }
        }
    }
}
void Afiseaza()
{
    for(int i = 2; i <= N; i++)
    {
        if(D[i] != oo)
            out<< D[i] << " ";
        else
            out<< " 0 ";
    }
}
int main()
{
    Citeste();
    Dijkstra(1);
    Afiseaza();
    return 0;
}