Cod sursa(job #2165859)

Utilizator SternulStern Cristian Sternul Data 13 martie 2018 14:04:10
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.58 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

const int NMAX = 50005;
const int oo = (1 << 31) - 1;

int n, m;
int D[NMAX];
bool InCoada[NMAX];

struct Compara
{
    bool operator()(int x, int y){
        return D[x] > D[y];
    }
};

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

priority_queue <int, vector <int>, Compara> Coada;

void Citeste()
{
    f>>n>>m;
    for(int i = 1;i<=m;i++)
    {
        int x, y , c;
        f>>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(unsigned 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])
                {
                    InCoada[Vecin] = true;
                    Coada.push(Vecin);
                }
            }

        }

    }
}

void Afiseaza()
{
    for(int i = 2;i <= n;i++)
    {
        if(D[i]!=oo)
            g<<D[i]<<" ";
        else g<<0<<" ";
    }
}

int main()
{
    Citeste();
    Dijkstra(1);
    Afiseaza();
    return 0;
}