Cod sursa(job #1086599)

Utilizator rares96cheseliRares Cheseli rares96cheseli Data 18 ianuarie 2014 13:06:24
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
const int inf = (1<<30)+1000000000;

int N, M, nod, D[50005];
struct muchie { int y, c; }aux;
struct cmp
{
    bool operator()(const int &a, const int &b)const
    {
        return (D[a]>D[b]);
    }
};
vector < muchie > G[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 < muchie > :: iterator it, final;

    while (!Heap.empty())
    {
        int nod=Heap.top(); Heap.pop();
        it=G[nod].begin(); final=G[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>>nod>>aux.y>>aux.c;
        G[nod].push_back(aux);
    }

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