c语言单链表的插入，删除，遍历，输出

C语言单链表的插入、删除、遍历、输出操作如下：

插入操作：

1. 在链表头部插入节点：

struct Node {
    int data;
    struct Node* next;
};

void insertAtBeginning(struct Node** head_ref, int new_data) {
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = (*head_ref);
    (*head_ref) = new_node;
}

2. 在链表尾部插入节点：

void insertAtEnd(struct Node** head_ref, int new_data) {
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    struct Node* last = *head_ref;
    new_node->data = new_data;
    new_node->next = NULL;
    if (*head_ref == NULL) {
        *head_ref = new_node;
        return;
    }
    while (last->next != NULL) {
        last = last->next;
    }
    last->next = new_node;
    return;
}

3. 在链表中间插入节点：

void insertAfter(struct Node* prev_node, int new_data) {
    if (prev_node == NULL) {
        printf("The given previous node cannot be NULL");
        return;
    }
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = new_data;
    new_node->next = prev_node->next;
    prev_node->next = new_node;
}

删除操作：

1. 删除链表头部节点：

void deleteAtBeginning(struct Node** head_ref) {
    if (*head_ref == NULL) {
        printf("The list is empty");
        return;
    }
    struct Node* temp = *head_ref;
    *head_ref = (*head_ref)->next;
    free(temp);
}

2. 删除链表尾部节点：

void deleteAtEnd(struct Node** head_ref) {
    if (*head_ref == NULL) {
        printf("The list is empty");
        return;
    }
    if ((*head_ref)->next == NULL) {
        free(*head_ref);
        *head_ref = NULL;
        return;
    }
    struct Node* temp = *head_ref;
    while (temp->next->next != NULL) {
        temp = temp->next;
    }
    free(temp->next);
    temp->next = NULL;
}

3. 删除链表中间节点：

void deleteNode(struct Node** head_ref, int key) {
    struct Node* temp = *head_ref, *prev;
    if (temp != NULL && temp->data == key) {
        *head_ref = temp->next;
        free(temp);
        return;
    }
    while (temp != NULL && temp->data != key) {
        prev = temp;
        temp = temp->next;
    }
    if (temp == NULL) {
        printf("The key is not present in the list");
        return;
    }
    prev->next = temp->next;
    free(temp);
}

遍历操作：

void printList(struct Node* node) {
    while (node != NULL) {
        printf("%d ", node->data);
        node = node->next;
    }
}

输出操作：

int main() {
    struct Node* head = NULL;
    insertAtEnd(&head, 6);
    insertAtBeginning(&head, 7);
    insertAtBeginning(&head, 1);
    insertAtEnd(&head, 4);
    insertAfter(head->next, 8);
    printf("Created Linked list is: ");
    printList(head);
    deleteNode(&head, 1);
    printf("\nLinked List after Deletion of 1: ");
    printList(head);
    deleteAtEnd(&head);
    printf("\nLinked List after Deletion at End: ");
    printList(head);
    deleteAtBeginning(&head);
    printf("\nLinked List after Deletion at Beginning: ");
    printList(head);
    return 0;
}

这是一个完整的单链表的插入、删除、遍历、输出的代码。