Cod sursa(job #2119891)

Utilizator vladsftVlad Safta vladsft Data 1 februarie 2018 18:51:25
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.81 kb
#include <fstream>
#include <vector>

using namespace std;

const int N = 100001;
vector <int> a[N];
int n, s, q[N], d[N], x, y, m;

ifstream in("bfs.in");
ofstream out("bfs.out");
void citire ()
{
    in >> n >> m >> s;
    for (int i = 0; i < m; i++)
    {
        in >> x >> y;
        a[x].push_back(y);
    }
    in.close();
}
int main()
{
    citire();
    for (int i = 1; i <= n; i++)
        d[i] = -1;
    int st = 0, dr = -1;
    q[++dr] = s;
    d[s] = 0;
    while (st <= dr)
    {
        x = q[st++];
        for (int i = 0; i < a[x].size(); i++)
        {
            y = a[x][i];
            if (d[y] == -1)
            {
                q[++dr] = y;
                d[y] = 1 + d[x];
            }
        }
    }
    for (size_t i = 1; i <= n; i++)
        out << d[i] << ' ';
    out.close();
    return 0;
}