Cod sursa(job #3192777)

Utilizator raresOObreja Rares raresO Data 13 ianuarie 2024 11:10:34
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.72 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)
    {
        if (cmin[x] != cmin[y])
        {
            return cmin[x] > cmin[y];
        }
        return x > y;
    }
};

priority_queue<int, vector<int>, ComparVf> 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(p);
    for (i = 1; i <= n; i++)
        cmin[i] = INF;
    cmin[p] = 0;
    while (!H.empty())
    {
        vfmin = H.top();
        H.pop();
        if (cmin[vfmin] == INF)
            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] = cmin[vfmin] + c;
                    H.push(x);
                }
            }
            fr[vfmin] = 1;
        }
    }
}
void afisare()
{
    int i;
    for (i = 2; i <= n; i++)
        if (cmin[i] != INF)
            fout << cmin[i] << ' ';
        else
            fout << 0 << ' ';
    fout << '\n';
}