【课题】若某算术表达式采用后置法表示（即逆波兰表达式），请编程计算该表达式的值。如：表达式(a+b*c)/d-e用后置法表示为abc*+d/e-。 -[ Topic ] If an arithmetic expression using the post method representation (i.e., inverse Poland expression ), please programming calculation of the value of the expression.