Topic description
Input two integer sequences. The first sequence represents the stack's push sequence. Please check whether the second sequence is the stack's pop-up sequence. Assume that all numbers pushed onto the stack are not equal. For example, the sequence 1, 2, 3, 4, 5 is the push sequence of a stack, the sequence 4, 5, 3, 2, 1 is a pop sequence corresponding to the stack sequence, but 4, 3, 5, 1, 2 It cannot be the pop sequence of the push sequence. (Note: the two sequences are of equal length)
Idea: Python judges whether the pop-up sequence of the stack is legal
# -*- coding:utf-8 -*-
class Solution:
def IsPopOrder(self, pushV, popV):
# write code here
if not pushV or len(pushV)!=len(popV):
return 0
stack = []
for v in pushV:
stack.append(v)
while len(stack) and stack[-1]==popV[0]:
stack.pop()
popV.pop(0)
if len(stack):
return 0
return 1