ruby實現石頭剪刀布游戲

代碼如下:
#encoding: utf-8
arr = ['石頭', '剪刀', '布']
win_arr = [['石頭', '剪刀'], ['剪刀', '布'], ['布', '石頭']]
#隨機computer的值，放入result數組中
result = [arr.sample]
while (true)
  puts "請輸入石頭、剪刀、布"
  input_value = gets.force_encoding("GBK").encode("UTF-8").chomp
  if arr.include? input_value
    result << input_value
    if result[0] == result[1]
      puts '平手'
    elsif win_arr.include? result
      puts '電腦獲勝'
    else
      puts '您獲勝了'
      break
    end
  else
    puts '輸入的值有誤，請輸入石頭、剪刀、布'
    next
  end
end