Cod sursa(job #2175128)

Utilizator ionuttiplea2001Tiplea Ionut ionuttiplea2001 Data 16 martie 2018 15:29:12
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.68 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int Nmax = 50005;
const int oo = ( 1 << 30 );

int N , M ;
int D[Nmax];
bool InCoada[Nmax] ;

vector < pair < int , int > > G[Nmax];
struct compara
{
    bool operator()( int x , int y)
    {
        return D[x] > D[y];
    }
};

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

void Citeste()
{
    fin >> N >> M ;
    for ( int i = 1; i <= M; i ++ )
    {
        int x , y , c;
        fin >> 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 )
            fout << D[i] << " ";
        else
            fout << "0 ";
    }
}
int main()
{
    Citeste();
    Dijkstra(1);
    Afiseaza();

    return 0;
}