Cod sursa(job #1466518)

Utilizator crysstyanIacob Paul Cristian crysstyan Data 29 iulie 2015 12:55:49
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 50001
#define inf 2000000000

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

int i, n, m, x, y, dist, d[NMAX];
bool visited[NMAX];

struct heap
{
    int x, y;
};

struct compare
{
    bool operator() (heap &a, heap &b)
    {
        return a.y > b.y;
    }
};

vector < heap > v[NMAX];
priority_queue < heap, vector < heap >, compare > pq;

void dijkstra()
{
    heap h;
    h.x = 1;
    h.y = 0;
    pq.push(h);

    while (pq.size())
    {
        int minim = pq.top().x;
        pq.pop();

        for (i = 0; i < v[minim].size(); ++ i)
            if (d[v[minim][i].x] > d[minim] + v[minim][i].y)
        {
            d[v[minim][i].x] = d[minim] + v[minim][i].y;
            pq.push(v[minim][i]);
        }

    }
}

int main()
{
    f >> n >> m;

    for (i = 1; i <= m; ++ i)
    {
        f >> x >> y >> dist;
        heap c;
        c.x = y;
        c.y = dist;
        v[x].push_back(c);
    }

    for (i = 2; i <= n; ++ i)
        d[i] = inf;

    dijkstra();

    for (i = 2; i <= n; ++i)
        if (d[i] == inf)
            g << "0 ";
        else
            g << d[i] << " ";
    return 0;
}