Cod sursa(job #2729895)

Utilizator codrut86Coculescu Ioan-Codrut codrut86 Data 25 martie 2021 15:54:25
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

const int N = 5e4 + 1;
const int INF = 1e9 + 15;

vector <pair <int, int>> a[N];
priority_queue <pair <int, int>> pq;
bitset <N> prelucrat;
int d[N], n, m;

int main()
{
    ifstream in("dijkstra.in");
    ofstream out("dijkstra.out");
    in >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int x, y, c;
        in >> x >> y >> c;
        a[x].push_back({y, c});
    }
    in.close();

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

    d[1] = 0;
    pq.push({0, 1});

    while (!pq.empty())
    {
        int x = pq.top().second;
        pq.pop();
        if (prelucrat[x]) continue;

        prelucrat[x] = 1;
        for (auto p: a[x])//parcurg succesorii lui x
        {
            int y = p.first, c = p.second;
            if (d[x] + c < d[y])
            {
                d[y] = d[x] + c;
                pq.push({-d[y], y});
            }
        }
    }

    for (int i = 2; i <= n; i++)
    {
        if (d[i] == INF) d[i] = 0;
        out << d[i] << " ";
    }
    out.close();
    return 0;
}