Cod sursa(job #1148921)

Utilizator Ionut228Ionut Calofir Ionut228 Data 21 martie 2014 12:14:49
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.46 kb
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

const int INF = 0x3f3f3f3f;

int N, M;
int Dmin[50002];
vector<pair<int, int> > V[50002];
queue<int> Q;
bool inqueue[50002];

void bellman_ford(int nod)
{
    memset(Dmin, INF, sizeof(Dmin));
    Dmin[1] = 0;

    Q.push(nod);
    inqueue[nod] = true;

    while (!Q.empty())
    {
        int now = Q.front();
        Q.pop();
        inqueue[now] = false;

        for (vector<pair<int, int> >::iterator it = V[now].begin(); it != V[now].end(); ++it)
        {
            if (Dmin[now] + it->second < Dmin[it->first])
            {
                Dmin[it->first] = Dmin[now] + it->second;
                if (!inqueue[it->first])
                {
                    Q.push(it->first);
                    inqueue[it->first] = true;
                }
            }
        }
    }
}

int main()
{
    fin >> N >> M;
    for (int i = 1, nod1, nod2, cost; i <= M; ++i)
    {
        fin >> nod1 >> nod2 >> cost;
        V[nod1].push_back(make_pair(nod2, cost));
        V[nod2].push_back(make_pair(nod1, cost));
    }

    bellman_ford(1);

    for (int i = 2; i <= N; ++i)
    {
        if (Dmin[i] == INF)
            fout << "0 ";
        else
            fout << Dmin[i] << ' ';
    }
    fout << '\n';

    fin.close();
    fout.close();
    return 0;
}