1、实现顺序栈的基本操作：构造空栈、入栈、出栈、取栈顶元素。 2、输入一包含’[‘ ‘]’ “(”和“)”的字符串，检测括号是否匹配（其中括号中能嵌套括号），并输出括号是否匹配的信息。 输入一个十进制数, 输出其对应的八进制数

1. 顺序栈的基本操作实现：

class Stack:
    def __init__(self):
        self.items = []

    def is_empty(self):
        return len(self.items) == 0

    def push(self, item):
        self.items.append(item)

    def pop(self):
        if self.is_empty():
            raise Exception("Stack is empty")
        return self.items.pop()

    def peek(self):
        if self.is_empty():
            raise Exception("Stack is empty")
        return self.items[-1]

2. 括号匹配检测实现：

def check_brackets(string):
    stack = Stack()
    for char in string:
        if char in ['[', '(']:
            stack.push(char)
        elif char in [']', ')']:
            if stack.is_empty():
                return False
            top = stack.peek()
            if (char == ']' and top == '[') or (char == ')' and top == '('):
                stack.pop()
            else:
                return False
    return stack.is_empty()

3. 十进制转八进制实现：

def decimal_to_octal(decimal):
    stack = Stack()
    while decimal > 0:
        remainder = decimal % 8
        stack.push(remainder)
        decimal //= 8
    octal = ''
    while not stack.is_empty():
        octal += str(stack.pop())
    return octal