Cod sursa(job #2718739)

Utilizator Costea_AlexandruCostea Alexandru Costea_Alexandru Data 9 martie 2021 09:11:01
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.36 kb

#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fi("dijkstra.in");
ofstream fo("dijkstra.out");
const int inf = 1000000000;
int n, m, d[50001];
bool f[50001];
struct compara {
    bool operator()(int x, int y)
    {
        return d[x] > d[y];
    }
};
vector <pair <int, int>> v[50005];
priority_queue < int, vector <int>, compara> q;

void Dijkstra(int p)
{
    int i, nod, vecin, cost;
    for (i = 1; i <= n; i++)
        d[i] = inf;
    d[p] = 0;
    q.push(p);
    f[p] = true;
    while (!q.empty())
    {
        nod = q.top();
        q.pop();
        f[nod] = false;
        for (size_t j = 0; j < v[nod].size(); j++)
        {
            vecin = v[nod][j].first;
            cost = v[nod][j].second;
            if (d[nod] + cost < d[vecin])
            {
                d[vecin] = d[nod] + cost;
                if (!f[vecin])
                {
                    q.push(vecin);
                    f[vecin] = true;
                }
            }
        }
    }
}

int main()
{
    int i, j, x, y, c;
    fi >> n >> m;
    for (i = 1; i <= m; i++)
    {
        fi >> x >> y >> c;
        v[x].push_back(make_pair(y, c));
    }
    Dijkstra(1);
    for (i = 2; i <= n; i++)
        if (d[i] != inf)
            fo << d[i] << " ";
        else fo << 0 << " ";
    return 0;
}