notebook.community

Edit and run

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 × 99.

Find the largest palindrome made from the product of two 3-digit numbers.



In [4]:

    
class Integer
  def palindromic?
    self.to_s == self.to_s.reverse
  end
end

12321.palindromic?









    Out[4]:





true



In [8]:

    
result = []

(111..999).lazy.each do |x|
  (111...999).lazy.each do |y|
    temp = x * y
    result << temp if temp.palindromic?
  end
end

result.max









    Out[8]:





906609