takapt

;;; This was installed by package-install.el.
;;; This provides support for the package system and
;;; interfacing with ELPA, the package archive.
;;; Move this code earlier if you want to reference
;;; packages in your .emacs.
(when
    (load
     (expand-file-name "~/.emacs.d/elpa/package.el"))
  (package-initialize))
(custom-set-variables

takapt

def f(i, a, b)
  a.to_s.size < 1000 ? f(i + 1, a + b, a) : i
end
puts f(2, 1, 1) #=> 4782

takapt

(1...1000).select{|i| i % 3 == 0 || i % 5 == 0}.inject(0, :+) # => 233168

takapt

(2...10**6).select{|i| i == i.to_s.split(//).inject(0){|s, c| s + c.to_i**5}}.inject(0, :+) # => 443839

takapt

dp = [1] + [0] * 200
[1, 2, 5, 10, 20, 50, 100, 200].each do |v|
  0.upto(200) do |i|
    dp[i] += dp[i - v] if i - v >= 0
  end
end
puts dp[200] # => 73682

takapt

puts (1..9).flat_map{|a| ((a + 1)..9).flat_map{|b| (1..9).flat_map{|i| [10 * a + i, 10 * i + a].product([10 * b + i, 10 * i + b]).map{|p, q| Rational(p, q)}.select{|w| w == Rational(a, b)}}}}.inject(:*).denominator

takapt

fact = (1..9).each_with_object([1]){|i, a| a << a[-1] * i}
puts (3..(6 * fact[9])).select{|n| n.to_s.split(//).map{|s| fact[s.to_i]}.inject(:+) == n}.inject(:+)

takapt

require 'prime'
puts (1...10**6).count{|n| s = n.to_s; (0...s.length).all?{|i| Prime.prime?((s[i..-1] + s[0...i]).to_i)}}

takapt

# -*- coding: utf-8 -*-
require 'cgi'
require 'open3'
require 'benchmark'
require 'httpclient'            # gem



class Validator
  def accepted?(answer, output)

takapt

puts (1...10**6).select{|i| i.to_s == i.to_s.reverse && i.to_s(2) == i.to_s(2).reverse}.inject(:+)