Cod sursa(job #1648331)

Utilizator crysstyanIacob Paul Cristian crysstyan Data 11 martie 2016 09:33:00
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.33 kb
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
#define NMAX 50005
#define inf 2000000000

using namespace std;

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

int i, n, m, d[NMAX], x, y, cost;
vector < pair < int, int > > v[NMAX];
bool visited[NMAX];

struct comp
{
    bool operator () (pair < int, int > &a, pair < int, int > &b)
    {
        return a.second > b.second;
    }
};

priority_queue < pair < int, int >, vector < pair < int, int > >, comp > pq;

void dijkstra()
{
    pq.push({1, 0});

    while (!pq.empty())
    {
        int curr = pq.top().first;
        pq.pop();

        if (!visited[curr])
        {
            visited[curr] = 1;

            for (auto & it : v[curr])
                if (!visited[it.first])
            {
                d[it.first] = min(d[it.first], d[curr] + it.second);
                pq.push({it.first, d[it.first]});
            }
        }
    }
}

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

    for (i = 1; i <= m; ++ i)
    {
        f >> x >> y >> cost;
        v[x].push_back(make_pair(y, cost));
    }

    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;
}