Cod sursa(job #2299524)

Utilizator ezioconnorVlad - Gabriel Iftimescu ezioconnor Data 9 decembrie 2018 17:51:35
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.64 kb
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

const int NMAX = 50001;
const int oo = (1 << 30);

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

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

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

priority_queue < int, vector < int >, comparaDistante > coada;

void citire()
{
    int x, y, c;
    in >> n >> m;
    for (int i = 1; i <= m; ++i)
    {
        in >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
    }
}

void dijkstra(int nodStart)
{
    int nodCurent, vecin, cost;
    for (int i = 1; i <= n; ++i)
        D[i] = oo;
    D[nodStart] = 0;
    coada.push(nodStart);
    inCoada[nodStart] = 1;
    while (!coada.empty())
    {
        nodCurent = coada.top();
        coada.pop();
        inCoada[nodCurent] = 0;
        for (size_t i = 0; i < G[nodCurent].size(); ++i)
        {
            vecin = G[nodCurent][i].first;
            cost = G[nodCurent][i].second;
            if (D[nodCurent] + cost < D[vecin])
            {
                D[vecin] = D[nodCurent] + cost;
                if (inCoada[vecin] == 0)
                {
                    coada.push(vecin);
                    inCoada[vecin] = 1;
                }
            }
        }
    }
}

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

int main()
{
    citire();
    dijkstra(1);
    afisare();
    return 0;
}