Cod sursa(job #2244162)

Utilizator cosmin.pascaruPascaru Cosmin cosmin.pascaru Data 22 septembrie 2018 12:38:48
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.1 kb
#include <fstream>
#include <vector>
#include <set>
#include <utility>
 
#define NMAX 50005
#define INF 1<<30
 
using namespace std;
 
int d[NMAX];
set < pair<int, int> > S;
vector< pair <int, int> > G[NMAX];
 
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
 
void Dijkstra()
{
    int dist, nod;
    S.insert(make_pair(0, 1));
 
    while(!S.empty())
    {
        dist = S.begin() -> first;
        nod = S.begin() -> second;
        S.erase(S.begin());
 
        for (int i = 0; i < G[nod].size(); ++i)
            if (d[G[nod][i].first] > d[nod] + G[nod][i].second)
            {
                d[G[nod][i].first] = d[nod] + G[nod][i].second;
                S.insert(make_pair(d[G[nod][i].first], G[nod][i].first));
            }
    }
}
int main()
{
    int n, m;
    int x, y , c;
    fin >> n >> m;
 
    for (int i = 0; i < m; ++i)
    {
        fin >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
    }
 
    for (int i = 2; i <= n; ++i)
        d[i] = INF;
 
    Dijkstra();
 
    for (int i = 2; i <= n; ++i)
        fout << ((d[i] == INF)? 0 : d[i]) << ' ';
    fout << '\n';
    return 0;
}