Cod sursa(job #1890695)

Utilizator medicinedoctoralexandru medicinedoctor Data 23 februarie 2017 13:54:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>

long a[100001][64], d[100001], n, i, j, q;

void read()
{
    std::ifstream f("bfs.in");
    long x, y, m;
    f >> n >> m >> q;
    for (i = 1; i <= n; i++)
        d[i] = -1, a[i][0] = 0;
    d[q] = 0;

    for (i = 1; i <= m; i++)
    {
         f >> x >> y;
        if (x != y)
            a[x][ ++a[x][0] ] = y;
    }
    f.close();
}

void solve()
{
    long x[100001], c;
    x[ x[0] = 1 ] = q;

    for (i = 1; i <= x[0]; i++)
        for (j = 1; j <= a[ x[i] ][0]; j++)
        {
            c = a[ x[i] ][j];
            if (d[c] == -1)
            {
                d[c] = d[ x[i] ] + 1;
                x[ ++x[0] ] = c;
            }
        }
}

void write()
{
    std::ofstream f("bfs.out");
    for (i = 1; i <= n; i++)
        f << d[i] << ' ';
    f.close();
}

int main()
{
    read();

    solve();

    write();

    return 0;
}