在C语言中如何实现双链表的基本操作（如插入节点、删除节点和遍历）使用尾插法？

在C语言中，使用尾插法（也叫“尾追法”）实现双链表的基本操作通常涉及以下几个步骤：

1. **结构体定义**:

typedef struct Node {
    int data;
    struct Node* next;
    struct Node* prev; // 双向链表特有的指向前一个节点的指针
} Node;

2. **插入节点** (尾部插入):

void insertAtEnd(Node** head, int data) {
    if (*head == NULL) {
        *head = (Node*)malloc(sizeof(Node));
        (*head)->data = data;
        (*head)->prev = NULL;
        (*head)->next = NULL;
    } else {
        Node* newNode = (Node*)malloc(sizeof(Node));
        newNode->data = data;
        newNode->prev = (*head)->prev;
        newNode->next = *head;
        if ((*head)->prev != NULL)
            (*head)->prev->next = newNode;
        else
            newNode->prev = NULL;
        (*head)->prev = newNode;
    }
}

3. **删除节点**:

void deleteNode(Node** head, int key) {
    Node* temp = *head;
    while (temp != NULL && temp->data != key) {
        temp = temp->next;
    }

    if (temp == NULL) return;

    // 如果要删除的是头结点
    if (temp == *head) {
        *head = temp->next;
        if (*head != NULL) (*head)->prev = NULL;
        free(temp);
    } else {
        temp->prev->next = temp->next;
        if (temp->next != NULL) temp->next->prev = temp->prev;
        free(temp);
    }
}

4. **遍历双链表** (尾部开始的反向遍历):

void printListBackward(Node* node) {
    while (node != NULL) {
        printf("%d ", node->data);
        node = node->prev;
    }
    printf("\n");
}