Leetcode Solution for "Number Complement" problem in Ruby

bitwise_complement.rb

=begin  
687.to_s(2)  # "1010101111"
"1010101111".to_i(2)   # 687
=end

def find_complement(num)
    num = num.to_s(2).chars
    num.map!{|i| i.to_i}
    for x in 0..num.size-1 do 
     if num[x]==0
      num[x] = 1 
     else 
      num[x] = 0 
     end
    end
    p num.join.to_i(2)
end