227. 基本计算器 II

为保证权益，题目请参考 227. 基本计算器 II(From LeetCode).

解决方案1

Python

class Node:
    def __init__(self):
        self.operation = ""
        self.left_operand = None
        self.right_operand = None


class Solution:
    def calculate(self, s: str) -> int: