how to get B+ matrix (warshall algorithm) in matlab?

Pseudocode:

// B = nxn binary matrix
// Bm = resulting matrix
for (i=1; i<=n; i++)
{
  for (j=1; j<=n; j++)
  {
    if (B[i,j] == 1)
    {
      for (k=1; k<=n; k++)
      {
        Bm[i,j] = B[i,j] | B[k,j];
      }
    }
  }
}

This is the warshall algorithm written (in my way) in matlab:

B = [1 1 0 0 0; 0 0 0 1 0; 0 0 0 0 1; 0 1 0 0 0; 0 0 0 0 0];

n = 5;

Bm = zeros(n);

for i = 1:n
    for j = 1:n
        if B(i,j) == 1
            for k = 1:n
                Bm(i,k) = B(i,k) | B(k,j);
            end
        end
    end
end

It works but, how can I improve the matrix loops?