Kata

Convert integer numbers to binary, without using the to_s(2) method.

n_to_bits(0) # => 0
n_to_bits(1) # => 1
n_to_bits(2) # => 10
n_to_bits(5) # => 101

The second optional argument passes the minimum length. If your binary number is shorter than this length, then pad zeros on the left hand side to fulfill this minimum length like so:

n_to_bits(2, 4) # => 0010
n_to_bits(2, 8) # => 00000010
n_to_bits(5, 8) # => 00000101