调试链表

Question

我正在尝试用 C 构建一个单链表库。我已经记下了所有代码，但有一个我找不到的错误，它使我的程序无法通过一些测试。

更具体一点。

每当我尝试删除包含某些数据的节点时，我的测试都会失败。该节点未被删除，我的消息说 "This data is not in the list" 被打印出来。

有人可以看一下并告诉我我缺少什么吗？

/* list_insertn: create a new node and insert it at the <n>th position,
    where the head is at position 1
   Parameters
   - node*: a pointer to the head of a linked list
   - char*: data to be stored in the new node
   - int: the position in which to insert the new node
   Return: a pointer to the head of the linked list */
node* list_insertn(node* list, char* input, int n){

    // Base case
    if(n <= 1){
        // Create the new node and allocate memory for it
        node *newNode = malloc(sizeof(struct s_node));

        // Insert new node
        newNode->next = list;

        // Allocate enough memory for the data input
        newNode->data = malloc(sizeof(char)*(strlen(input) +1));

        // Place data in the node
        strcpy(newNode->data, input);
        return newNode;
    }

    //If we exceed list length append at the end
    if(list->next == NULL){
        list->next = list_insert_tail(NULL, input);
    }

    // Advance through the list if not at the specified position
    list->next = list_insertn(list->next, input, n-1);
    return list;
}

/* list_remove: remove the node containing specific data; if multiple nodes
    contain the data, remove the node nearest to the head
   Parameters
   - node*: a pointer to the head of a linked list
   - char*: data that, if found in one of the nodes in the list, indicates
      the node to remove (in the case of multiple nodes containing the data,
      remove the node nearest to the head)
   Return: a pointer to the head of the linked list */
node* list_remove(node* list, char* input){
    //As long as we have elemnts
    if(list != NULL){
        // We check to see if they have the same data
        if(list->data == input){
            // We remove the link
            node *newNextNode = list->next;

            // Remove the data
            free(list->data);

            // An remove the node itself when done
            free(list);
            return newNextNode;
        }
            //If it\'s not the correct data we move forward through the list
        else{
            // And check following nodes recursively
            list->next = list_remove(list->next, input);
            return list;
        }
    }
        // But if we reach the end of the list
    else{
        // We print a warning message
        printf("Specified data does not exist in any of the nodes");
        return NULL;
    }
}

出于学术安全考虑，我必须删除部分代码。我会只留下有错误的部分。

Answer 1

我已经为你调试好了。修复：

在 list_insertn 中，将 "If we exceed list length append at the end" 注释后的整个 if 语句替换为：
```
if(list == NULL){
    return list_insert_tail(list, input);
}
```
在list_remove中，将"We check to see if they have the same data"评论后的测试替换为：
```
if(strcmp(list->data, input) == 0){
```
与常规 clean-up 一样，将所有 \n 实例修复为 \n，并将任何缺失的 \n 字符添加到需要它们的各种 printf 格式字符串的末尾。

调试链表

Debugging a linked-list

c

debugging

linked-list

singly-linked-list