摘要：
# -*- coding: cp936 -*-#构建表达式二叉树import Stack#if 'ch' is opreator,then return True,otherwise return Falsedef isOperator(ch): if '+' == ch or '-' == ch or\ '*' == ch or '/' == ch or\ '(' == ch or ')' == ch or\ '#' == ch: return True retur 阅读全文
