Cod sursa(job #2270838)

Utilizator PetrescuAlexandru Petrescu Petrescu Data 27 octombrie 2018 17:18:04
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <queue>
#include <utility>
#include <fstream>
#define NMAX 50000
#define inf 1000000000

using namespace std;

priority_queue<pair<int, int>>heap;
int d[NMAX + 1];
vector<pair<int ,int>>g[NMAX + 1];

void dijkstra(int start)
{
    int i;

    heap.push({0, start});

    while(!heap.empty())
    {
        pair<int, int>nod = heap.top();
        heap.pop();
        pair<int, int>vecin;

        for(i = 0; i < g[nod.second].size(); i++)
        {
            vecin.second = g[nod.second][i].first;
            vecin.first = g[nod.second][i].second + -1 * nod.first;

            if(d[vecin.second] > vecin.first)
            {
                d[vecin.second] = vecin.first;
                heap.push({-vecin.first, vecin.second});
            }
        }
    }
}

int main()
{
    int n, m, i, x, y, z;
    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");

    fin >> n >> m;

    for(i = 1; i <= m; i++)
    {
        fin >> x >> y >> z;
        g[x].push_back({y, z});
    }

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

    d[1] = 0;

    dijkstra(1);

    for(i = 2; i <= n; i++)
        if(d[i] != inf)fout << d[i] << " ";
        else fout << 0 << " ";

    fin.close();
    fout.close();

    return 0;
}