问题

def split_parentheses(input_string):
    result = []
    stack = []
    for char in input_string:
        if char == '(':
            stack.append(char)
        elif char == ')':
            if len(stack) > 0 and stack[-1] == '(':
                stack.pop()
                if len(stack) == 0:
                    result.append(''.join(stack))
                    stack = []  # clear stack for the next group
            else:
                return "Invalid input string: parentheses not perfectly matched."
    if len(stack) > 0:
        return "Invalid input string: parentheses not perfectly matched."
    return result

def wrap_with_parentheses(string):
    return f'({string})'

input_string = input("Enter a string of perfectly matched parentheses and whitespace: ")
result = split_parentheses(input_string)
result = list(map(wrap_with_parentheses, result))
print(result)

Input:	( ()) ((()()())) (()) ()		Output:	['(())', '((()()()))', '(())', '()']
Input:	() (( ( )() ( )) ) ( ())		Output:	['()', '((()()()))', '(())']

def split_parentheses(input_string):
    result = []
    stack = []
    for char in input_string:
        if char == '(':
            stack.append(char)
        elif char == ')':
            if len(stack) > 0 and stack[-1] == '(':
                stack.pop()
                if len(stack) == 0:
                    result.append(''.join(stack))
                    stack = []  # clear stack for the next group
            else:
                return "Invalid input string: parentheses not perfectly matched."
    if len(stack) > 0:
        return "Invalid input string: parentheses not perfectly matched."
    return result

def wrap_with_parentheses(string):
    return f'({string})'

input_string = input("Enter a string of perfectly matched parentheses and whitespace: ")
result = split_parentheses(input_string)
result = list(map(wrap_with_parentheses, result))
print(result)

答案1

得分: 2

一些问题：

* 在内部的 `if` 块中，栈是空的（已经测试为空），所以 `''.join(stack)` 将始终是一个空字符串，并且清除栈是一个无用的操作，因为它已经是空的。

* 由于你弹出了所有的 `(` 并且栈从不接收任何 `)`，所以没有办法从栈中重建最终的字符串。你需要一个单独的变量来收集括号。这可以是一个字符串变量。

* 用另一对括号包裹结果毫无意义，因为它只是创造了与输入无关的括号。所以去掉 `wrap_with_parentheses`。

其他备注：

* 由于栈只接收 `(` 字符，你实际上不需要这些字符（它还能是什么？），只需要长度。为此，你可以使用一个数值变量，比如 `depth`。它将对应于 `len(stack)`，而不需要实际上拥有栈。

这是你代码的修改版：

```python
def split_parentheses(input_string):
    result = []
    depth = 0  # 使用这个代替栈
    current = ""  # 这个变量将收集作为结果中的单个条目的字符串
    for char in input_string:
        if char in "()":
            current += char  # 收集所有的括号
        if char == '(':
            depth += 1
        elif char == ')':
            depth -= 1
            if depth < 0:
                return "无效的输入字符串：括号不匹配。"
            if depth == 0:
                result.append(current)
                current = "" # 清除字符串以便下一个组
    if depth:
        return "无效的输入字符串：括号不匹配。"
    return result


input_string = input("输入一个包含 perfectly matched 括号和空格的字符串：")
result = split_parentheses(input_string)
print(result)

<details>
<summary>英文:</summary>

Some issues:

* In the inner `if` block, the stack is empty (it was tested to be empty), so `&#39;&#39;.join(stack)` will always be an empty string, and clearing the stack is a useless operation, since it is already empty.

* Since you pop all `(` from the stack and the stack never receives any `)`, there is no way to reconstruct the final string from the stack. You need a separate variable to collect the parentheses. This could be a string variable. 

* It makes no sense to wrap the results with another pair of parentheses as it just invents parentheses that have no relation with the input. So drop `wrap_with_parentheses`. 

Other remark:

* As the stack only receives `(` characters, you don&#39;t actually need those characters (what else could it be?), but only the length. For that you can use a numeric variable, like `depth`. It would correspond to `len(stack)` without actually having the stack.

Here is a correction of your code:

def split_parentheses(input_string):
result = []
depth = 0 # Use this instead of a stack
current = "" # This variable will collect the string that will be a single entry in the result
for char in input_string:
if char in "()":
current += char # Collect all the parentheses
if char == '(':
depth += 1
elif char == ')':
depth -= 1
if depth < 0:
return "Invalid input string: parentheses not perfectly matched."
if depth == 0:
result.append(current)
current = "" # clear string for the next group
if depth:
return "Invalid input string: parentheses not perfectly matched."
return result

input_string = input("Enter a string of perfectly matched parentheses and whitespace: ")
result = split_parentheses(input_string)
print(result)

</details>