Cod sursa(job #1092387)

Utilizator rares96cheseliRares Cheseli rares96cheseli Data 26 ianuarie 2014 22:52:31
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

const int inf = (1<<30);
int N, M, x, D[50005];
struct muchii{ int y, c; }aux;
struct cmp
{
    bool operator()(const int &a, const int &b)const
    {
        if (D[a]>D[b]) return 1;
        return 0;
    }
};

vector < muchii > v[50005];
priority_queue < int, vector < int >, cmp > Heap;

void Dijkstra(int sursa)
{
    for (int i=1; i<=N; ++i) D[i]=inf;
    D[sursa]=0; Heap.push(sursa);
    vector < muchii > :: iterator it, final;

    while (!Heap.empty())
    {
        int nod=Heap.top(); Heap.pop();
        it=v[nod].begin(); final=v[nod].end();
        for (; it!=final; ++it )
            if (D[nod]+it->c < D[it->y])
                D[it->y]=D[nod]+it->c, Heap.push(it->y);
    }
}

int main()
{
    f>>N>>M;
    for (int i=1; i<=M; ++i)
        f>>x>>aux.y>>aux.c, v[x].push_back(aux);

    Dijkstra(1);
    for (int i=2; i<=N; ++i)
        if (D[i]==inf) g<<0<<' ';
            else g<<D[i]<<' ';

    return 0;
}