我正在尝试创建一个函数，该函数使用 linked list 检查表达式是否平衡（左括号数 = 右括号数）或不平衡。但是我的函数总是给出“不平衡”作为输出。

#include <stdio.h>
#include <stdlib.h>

struct LL
{
    char data;
    struct LL *next;
};

int isEmpty(struct LL *top)
{
    if (top == NULL)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

int isFull(struct LL *top)
{
    struct LL *n = malloc(sizeof(struct LL *));
    if (n == NULL)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

struct LL *push(struct LL *top, char x)
{
    if (isFull(top))
    { 
        printf("Stack Overflow\n");
    }
    else
    {
        struct LL *n = malloc(sizeof(struct LL));
        n->data = x;
        n->next = top;
        top = n;
    }
    return top;
 }

 struct LL *pop(struct LL *top)
 {
    if (isEmpty(top))
    {
        printf("Stack Underflow\n");
    }
    else
    {
        struct LL *n = malloc(sizeof(struct LL));
        n = top;
        top = top->next;
        free(n);
    }
    return top;
 }

 int BracketBalancing (char *exp)
 {
    struct LL *top = malloc(sizeof(struct LL));
    top->next = NULL;
    for (int i = 0; exp[i] != '\0'; i++)
    {
        if (exp[i] == '(')
        {
            push(top, exp[i]);
        }
        else if (exp[i] == ')')
        {
            if (isEmpty(top))
            {
                return 0;
            }
            pop(top);
        }
    }
    if (isEmpty(top))
    {
        return 1;
    }
    else
    {
        return 0;
    }
  }

主要代码：

int main(int argc, char const *argv[])
{
    int n;
    char *expression = (char *)malloc(sizeof(char));
    printf("Enter the length of the expression for Bracket Balancing\n");
    scanf("%d", &n);
    printf("Enter the expression for Bracket Balancing\n");
    for (int i = 0; i < n; i++)
    {
        scanf("%c ", &expression[i]);
    }
    getchar();
    if (BracketBalancing(expression))
    {
        printf("The expression is balanced\n");
    }
    else if (!BracketBalancing(expression))
    {
        printf("This expression is unbalanced\n");
    }
    return 0;
}

例如：

输入：

Enter the length of the expression for Bracket Balancing 
4
Enter the expression for Bracket Balancing
1+()

输出：

This expression is unbalanced

在上面的例子中，没有。开括号 = 没有。右括号（这是一个平衡的表达式），但生成的输出仍然是“这个表达式是不平衡的”。请更正我的代码。