Cod sursa(job #2722366)

Utilizator mihai03Mihai Grigore mihai03 Data 12 martie 2021 19:48:06
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.54 kb
#include <fstream>
#include <vector>
#include <queue>
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 comparaDistante
{
    bool operator() (int x, int y)
    {
        return D[x] > D[y];
    }
};

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

void Dijkstra(int nodStart)
{
    for(int i = 1; i <= n; ++i)
        D[i] = oo;
    D[nodStart] = 0;

    Coada.push(nodStart);
    InCoada[nodStart] = 1;

    while(!Coada.empty())
    {
        int nodCurent = Coada.top();
        Coada.pop();
        InCoada[nodCurent] = 0;

        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)
                {
                    InCoada[Vecin] = true;
                    Coada.push(Vecin);
                }
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        int x, y, c;
        fin >> x >> y >> c;

        G[x].push_back({y, c});
    }

    Dijkstra(1);

    for(int i = 2; i <= n; ++i)
    {
        if(D[i] == oo) fout << 0 << " ";
        else fout << D[i] << " ";
    }
    return 0;
}