Cod sursa(job #2581600)

Utilizator blotucosmincosmin blotucosmin Data 15 martie 2020 15:16:47
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>
#include <queue>
#include <vector>
#define NMAX 50005
#define oo (1 << 30)

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

int d[NMAX];
bool viz[NMAX];

vector < pair < int, int > > v[NMAX];

struct elem
{
    bool operator()(int x, int y)
    {
        return d[x] > d[y];
    }
};

priority_queue < int, vector < int >, elem> Q;

int n, m, i, x, y, c, k, cost;

int main()
{
    f >> n >> m;
    for(i = 1; i <= m; ++ i)
    {
        f >> x >> y >> c;
        v[x].push_back(make_pair(y, c));
    }
    for(i = 1; i <= n; ++ i)
        d[i] = oo;
    d[1] = 0;
    Q.push(1);
    viz[1] = 1;
    while(!Q.empty())
    {
        k = Q.top();
        Q.pop();
        viz[k] = 1;
        for(int i = 0; i < v[k].size(); ++ i)
        {
            x = v[k][i].first;
            cost = v[k][i].second;
            if(d[k] + cost < d[x])
            {
                d[x] = d[k] + cost;
                if(viz[x] == 0)
                {
                    viz[x] = 1;
                    Q.push(x);
                }
            }
        }
    }
    for(i = 2; i <= n; ++ i)
        if(d[i] == oo)
            g << "0" << " ";
        else
            g << d[i] << " ";
    return 0;
}