Cod sursa(job #2069030)

Utilizator alexilasiAlex Ilasi alexilasi Data 18 noiembrie 2017 11:47:45
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.37 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
#define NM 50001
#define INF 2000000000

struct arc
{
    int c, y;
};
int d[NM], n, m, inQ[NM];
struct compar
{
    bool operator() (int x, int y)
    {
        return d[x] > d[y];
    }
};
vector <arc> G[NM];
priority_queue <int, vector < int >, compar> Q;


void citeste()
{
    arc u;
    int i, m, x;

    fin>>n>>m;
    for(i = 1; i <= m; ++i)
    {
        fin>>x>>u.y>>u.c;
        G[x].push_back(u);
    }
}
void Dijkstra(int x)
{
    int i, im, y, c, lg;

    for(i = 1; i <= n; ++i) d[i] = INF;
    d[x] = 0;

    Q.push(x);
    inQ[x] = 1;

    while(!Q.empty())
    {
        im = Q.top();
        Q.pop();
        inQ[im] = 0;

        for(i = 0; i < G[im].size(); ++i)
        {
            y = G[im][i].y;
            c = G[im][i].c;

            lg = d[im] + c;
            if(lg < d[y])
            {
                d[y] = lg;
                if(inQ[y] == 0)
                {
                    Q.push(y);
                    inQ[y] = 1;
                }
            }
        }
    }

    for(i = 2; i <= n; ++i)
        if(d[i] < INF)
            fout<<d[i]<<' ';
        else fout<<0<<' ';

}
int main()
{
    citeste();
    Dijkstra(1);

    return 0;
}