euler12.rb

   1 load 'divisors.rb'
   2
   3 require 'logger'
   4 $log = Logger.new(STDERR)
   5 $log.level = Logger::WARN
   6
   7
   8 # The nth triangle number
   9 def triangle(n)
  10   n * (n + 1) / 2
  11 end
  12
  13 def first_triangle_number_with_more_than_n_divisors(n)
  14   i = 1
  15   while triangle(i).number_of_divisors <= 500
  16     $log.info { "Triangle number #{i} is #{triangle(i)}, which has #{triangle(i).number_of_divisors} divisors" }
  17     i += 1
  18   end
  19   $log.info { "Triangle number #{i} is #{triangle(i)}, which has #{triangle(i).number_of_divisors} divisors" }
  20   triangle i
  21 end
  22
  23 if __FILE__==$0
  24   puts first_triangle_number_with_more_than_n_divisors(500)
  25 end