"Hit and Blow" an approach to http://vipprog.net/wiki/exercise.html#ffeaab60

hit_and_blow.rb

# an approach to
#   * http://vipprog.net/wiki/exercise.html#ffeaab60

# tested Ruby 1.9.3

$VERBOSE = true

class Array
  def uniq?
    dup.uniq!.nil?
  end
end
  
Answer = Struct.new :hit, :bolow do
  def initialize(*args)
    @rights = args.pop
    super(*args)
  end
  
  def to_s
    each_pair.select{|k, v|v > 0}.map{|k, v|[v, k].join}.join(' ')
  end
  
  def correct?
    hit == @rights.length
  end
end

LENGTH = 4

until (rights = LENGTH.times.map{rand(9) + 1}; rights.uniq?)
end

puts "Can you guess the number that I'm thinking of?"

loop do
  result = Answer.new 0, 0, rights

  begin
    puts "Input #{LENGTH} unique numbers"
    numbers = gets.chomp.chars.map{|s|Integer s}
    raise ArgumentError unless numbers.length == rights.length
    raise ArgumentError unless numbers.uniq?
  rescue
    retry
  else
    numbers.each_with_index do |number, index|
      case rights.index(number)
      when index
        result.hit += 1
      when Fixnum
        result.bolow += 1
      end
    end
    
    puts result
    break if result.correct?
  end
end

puts 'Great!'

hit_and_blow2.rb

#!/usr/bin/ruby -w

class Array
  def uniq?
    dup.uniq!.nil?
  end
end

class Answer
  def self.generate(length)
    raise ArgumentError unless length >= 2

    until (numbers = length.times.map{rand(9) + 1}; numbers.uniq?)
    end
    numbers
  end

  def initialize(yours, length)
    @yours, @rights, @counts = yours, self.class.generate(length), nil
    raise ArgumentError unless @yours.length == @rights.length
    raise ArgumentError unless @yours.uniq?
  end
  
  def to_s
    [].tap {|r|
      r << "#{hit}hit" if hit > 0
      r << "#{blow}blow" if blow > 0
    }.join(' ')
  end
  
  def correct?
    @yours == @rights
  end
  
  def hit
    counts[:hit]
  end
  
  def blow
    counts[:blow]
  end
  
  private
  
  def counts
    @counts ||= Hash.new(0).tap {|r|
      @yours.each_with_index do |number, index|
        case @rights.index(number)
        when index
          r[:hit] += 1
        when Fixnum
          r[:blow] += 1
        end
      end
    }
  end
end

begin
  puts "Input length"
  length = Integer gets
rescue
  retry
else
  
end

loop do
  begin
    puts "Input #{length} unique numbers"
    numbers = gets.chomp.chars.map{|s|Integer s}
    answer = Answer.new numbers, length
  rescue
    retry
  else
    puts answer
    break if answer.correct?
  end
end

puts 'You Great'