设计一个猜数字游戏的类，让用户可以使用该类进行猜数字游戏。该类应包括一个随机数、游戏上限和游戏下限3个成员变量，同时包含判断是否猜测正确以及返回上限和返回下限等方法，并编写主程序演示该类的用法。（提示：猜数字游戏的功能介绍，有系统随机生成一个1到100之间的整数，由用户通过不断的输入数字来进行猜测，每次猜测失败，都根据用户新输入的数进行范围的提示。）-A number guessing game design class, so that users can use this class to number guessing game. This class should include a random number, game upper and lower limit of three members of the game variables that contain both determine whether the guess is correct and return to the upper and lower back and other methods, and the preparation of the main program demonstrates the usage of the class. (Hint: number guessing game detail, a systematic random integer between 1 and 100, through continuous input by the user to guess numbers, each time speculation fails, all based on user input the number of the new range of tips for .)