=begin
Divide & Conquer 를 이용하여 거듭제곱 구하기

http://dev.heartsavior.net/287
=end

def power(number, exponent)
  return 1 if 0 == exponent
  return number if 1 == exponent

  (0 == exponent & 1) ?
    power(number, exponent / 2) ** 2 :
    (power(number, (exponent - 1) / 2) ** 2) * number
end

puts "2^200 = " + power(2, 200).to_s

2^200 = 1606938044258990275541962092341162602522202993782792835301376