Cod sursa(job #1171105)

Utilizator rogoz.bogdanRogoz Bogdan rogoz.bogdan Data 15 aprilie 2014 10:00:03
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <fstream>
#include <vector>
#include <queue>
#define MX 50001
using namespace std;

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

struct vecin
{
    int j,c;    //tinem minte nodul vecin si lungimea muchiei
};

struct nod
{
    int i,*d;    //numarul nodului si distanta de la 1 la acesta
}t[MX];

struct comp
{
    bool operator() (nod a, nod b)
    {
        return (*(a.d) > *(b.d));
    }
};

int n,m;
int d[MX];
queue<vecin> v[MX];
priority_queue<nod, vector<nod>, comp> p;

void citire()
{
    int i,a,b,c;
    vecin x;
    fin>>n>>m;
    for(i=1; i<=m; i++)
    {
        fin>>a>>b>>c;
        x.j = b;
        x.c = c;
        v[a].push(x);
    }

    for(i=1; i<=n; i++)
    {
        t[i].i = i;
        t[i].d = &d[i];
    }
}

void dijkstra()
{
    p.push(t[1]);
    nod x;
    vecin y;
    int i,r;
    while(!p.empty())
    {
        x = p.top();
        p.pop();
        i = x.i;
        while(!v[i].empty())
        {
            y = v[i].front();
            v[i].pop();
            r = *(t[i].d) + y.c;
            if(d[y.j]==0 || r<d[y.j])
            {
                d[y.j] = r;
            }
            p.push(t[y.j]);
        }
    }
}

int main()
{
    citire();
    dijkstra();
    for(int i=2; i<=n; i++) fout<<d[i]<<' ';

    fin.close(); fout.close();
    return 0;
}