剑指offer——栈的压入弹出序列

# -*- coding:utf-8 -*-
class Solution:
    def IsPopOrder(self, pushV, popV):
        # write code here
        if len(pushV)!=len(popV):
            return False
        elif pushV==popV or pushV==popV[::-1]:
            return True
        elif len(pushV)==len(popV)==1 and pushV!=popV:
            return False
        elif pushV[-1]==popV[0]:
            return self.IsPopOrder(pushV[:-1], popV[1:])
        else:
            index=pushV.index(popV[0])
            stack,not_stack=pushV[:index],pushV[index+1:]
            return self.IsPopOrder(not_stack, popV[1:1+len(not_stack)])and stack[::-1]==popV[1+len(not_stack):]