Cod sursa(job #3192800)

Utilizator raresOObreja Rares raresO Data 13 ianuarie 2024 11:18:56
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.75 kb
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 50002
#define INF 1000000002

using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
int n, p = 1;

vector<pair<int, int>> G[NMAX];
int cmin[NMAX];
int fr[NMAX];

// class ComparVf
// {
// public:
//     bool operator()(int x, int y)
//     {
//         return cmin[x] > cmin[y];
//     }
// };

priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> H;

void citire();
void dijkstra();
void afisare();
int main()
{
    citire();
    dijkstra();
    afisare();
    return 0;
}

void citire()
{
    int i, j, c, m, k;
    pair<int, int> vf;
    fin >> n >> m;
    for (k = 0; k < m; k++)
    {
        fin >> i >> j >> c;
        vf.first = j;
        vf.second = c;
        G[i].push_back(vf);
    }
}

void dijkstra()
{
    int i, x, vfmin, c;
    H.push(make_pair(0, p));
    for (i = 1; i <= n; i++)
        cmin[i] = -1;
    cmin[p] = 0;
    while (!H.empty())
    {
        vfmin = H.top().second;
        H.pop();
        if (cmin[vfmin] == -1)
            break;
        if (!fr[vfmin])
        {
            for (i = 0; i < G[vfmin].size(); i++)
            {
                x = G[vfmin][i].first;
                c = G[vfmin][i].second;

                if (cmin[x] > cmin[vfmin] + c || cmin[x] == -1)
                {
                    cmin[x] = cmin[vfmin] + c;
                    H.push(make_pair(cmin[x], x));
                }
            }
            fr[vfmin] = 1;
        }
    }
}
void afisare()
{
    int i;
    for (i = 2; i <= n; i++)
        if (cmin[i] != -1)
            fout << cmin[i] << ' ';
        else
            fout << 0 << ' ';
    fout << '\n';
}