说明：  分析用堆栈解析算术表达式的基本方法。给出的示例代码能解析任何包括+，-，*，/，()和0到9数字组成的算术表达式。
(The Basic Method of Arithmetical Expressions for Analytical Stack. The given sample code can parse any arithmetic expression consisting of+,-,*, /, () and 0 to 9 numbers)