Sha256: 3f4fa3ad86795d1327fa275dee73f0a77ece64d6ddc02114ddc34b8e97df0e9b
Contents?: true
Size: 416 Bytes
Versions: 14
Compression:
Stored size: 416 Bytes
Contents
# coding: utf-8
class Integer
# A Dudeney number is a positive integer that is a perfect cube such that
# the sum of its decimal digits is the cube root of the number.
#
# Returns true if self is a Dudeney number; false otherwise.
#
# 4913.dudeney? #=> true
# 5832.dudeney? #=> true
# 98.dudeney? #=> false
#
def dudeney?
Math.cbrt(self) == self.digits.reduce(:+)
end
end
Version data entries
14 entries across 14 versions & 1 rubygems