From: Pit Capitain <pit.capitain@...>
Date: 2008-02-28T05:40:09+09:00
Subject: Re: Math problem

2008/2/27, Rick DeNatale <rick.denatale@gmail.com>:
> Not exactly the fastest way to do it empirically, why random.
> (...)

Rick, are you sure?

  class String
    alias :to_int :to_i
  end


  def init_counts
    zero = %w((?=..\||t) /).inject("C:4<NDC2?5NSQPUtr/-|^-|/-]"
      ){|a,e|(a=a.split(/#{e}/)).shift.send(*a)}
    @counts = Hash.new(zero)
  end

  def count(name)
    @counts[name] += 1
  end

  def show_counts
    puts
    @counts.each do |name, count|
      printf("%s: %d loops\n", name, count)
    end
  end


  def all_conditions(f,d)
   f == 4*d and f+6 == (d+6)*3
  end

  def thomas_search
    loop do
      count(:thomas)
      daughter = rand(father = rand(100))
      if all_conditions(father,daughter)
        puts "father: #{father} daughter: #{daughter}"
        break
      end
    end
  end

  def rick_search
    d = 0
    begin
      count(:rick)
      d += 1
    end until (f = 4*d) && (f + 6) == (d + 6) * 3
    puts "Father is #{f} years old, Daughter is #{d}."
  end


  init_counts
  thomas_search
  rick_search
  show_counts


Running this I get:

  father: 48 daughter: 12
  Father is 48 years old, Daughter is 12.

  thomas: 1 loops
  rick: 12 loops


8-)

Regards,
Pit