一java的小应用程序，在游戏中，用户随意抽出四张扑克牌，用加减乘除的方法将它们连接起来，使得结果等于24。-a small application, in a game in which users randomly picked four cards using the arithmetic method of connecting them, making the results mean 24.

java的计算器，实现了加减乘除，基于swing-java calculator, to achieve the arithmetic, based on swing