一个保护多线程应用中共享资源的例子。作者： Xiangyang Liu -protect a multi-threaded application resource-sharing example. Author : Liu Xiangyang

计算表达式是实现课程设计语言的基本问题之一,也是栈的应用的一个典型例子(Expression is to achieve one of the basic problems of curriculum design language, is also a typical example of the application of the stack)