double-square-number.rb

#!/usr/bin/env ruby

def integer?(number)
  (number % 1) == 0
end

def double_square_number?(number)
  sqrt = Math.sqrt(number)
  if integer?(sqrt)
    [sqrt.to_i, 0]
  else
    sqrt.floor.downto(1) do |n|
      if integer?(m = Math.sqrt(number - n ** 2))
        return [n, m.to_i]
      end
    end
    return false
  end
end

for i in 1..104 do
  puts "#{i} => #{double_square_number?(i).inspect}"
end