Cod sursa(job #2425579)

Utilizator alexnigaNiga Alexandru alexniga Data 24 mai 2019 21:47:41
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <iostream>
#include <fstream>
#include <vector>
#define MAX 100005
#include <queue>
using namespace std;

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

vector <vector <int> > G(MAX);
int n, m, s;
vector <int> viz(MAX, 0);

vector<int> BFS(int start)
{
    queue <int> q;
    q.push(start);
    vector <int> d(n + 1, -1);
    d[start] = 0;

    while(!q.empty())
    {
        int nod = q.front();
        q.pop();
        for (auto i: G[nod])
        {
            if ((d[i] > d[nod] + 1) || d[i] == -1)
                {
                    d[i] = d[nod] + 1;
                    q.push(i);
                }
        }
    }
    return d;

}

int main()
{
    f >> n >> m >> s;

    for (int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        G[x].push_back(y);
    }
    vector <int> ffinal(n + 1);
    ffinal = BFS(s);
    for (int i = 1; i <= n; i++)
        g << ffinal[i] << " ";

        return 0;
}