leetcode385

 1 class Solution:
 2     def deserialize(self, s: str) -> NestedInteger:
 3         
 4         if s[0] != '[':
 5             return NestedInteger(int(s))
 6         
 7         stack = []
 8         # num为数字，sign为符号为，is_num为前一个是否为数字
 9         num, sign, is_num = 0, 1, False
10         
11         for c in s:
12             if c.isdigit():
13                 num = num * 10 + int(c)
14                 is_num = True
15             elif c == '-':
16                 sign = -1
17             elif c == '[':
18                 stack.append(NestedInteger())
19             elif c == ',' or c == ']':
20                 # 把刚才遇到的数字append进去
21                 if is_num:
22                     cur_list = stack.pop()
23                     cur_list.add(NestedInteger(sign * num))
24                     stack.append(cur_list)
25                 num, sign, is_num = 0, 1, False
26 
27                 # 此时为嵌套列表
28                 if c == ']' and len(stack) > 1:
29                     cur_list = stack.pop()
30                     stack[-1].add(cur_list)
31 
32         return stack[0]

参考：https://leetcode-cn.com/problems/mini-parser/solution/python3ti-mu-bu-nan-zhi-xu-li-qing-luo-ji-by-salti/

一般来说，这种差评如潮的题目，又可能不是题目难，而是题目描述不清楚，对人有误导。本题似乎就存在这个问题。