c - 从链表中递归删除数字

Question

大家好我做了一个函数，它根据你想从链表中删除的数字递归地从链表中删除。但是在删除之后，如果我试图打印列表的堆栈，并且出现运行时错误，因为在删除之后，数字的位置什么也没有。我怎样才能完成代码？

 struct node* delete_item(struct node* head, int num)
{
    if (head == NULL) { // Found the tail
        printf("not found\n");
        return NULL;
    }
    else if (head->data == num) 
    { // Found one to delete
        head = head->next;
        free(head);
        printf("num founded");
        return head->next;
    }
    else 
    { // Just keep going
        head->next = delete_item(head->next, num);
        return head;
    }
}

Answer 1

您释放了应返回的内容并解除了指向已释放内容的指针的引用。这是错误的。

你应该引入一个缓冲区来存储应该返回的内容。

struct node* delete_item(struct node* head, int num)
{
    if (head == NULL) { // Found the tail
        printf("not found\n");
        return NULL;
    }
    else if (head->data == num) 
    { // Found one to delete
        struct node* next = head->next;
        free(head);
        printf("num founded");
        return next;
    }
    else 
    { // Just keep going
        head->next = delete_item(head->next, num);
        return head;
    }
}