单链表的头尾插入和删除C语言

单链表的头尾插入和删除C语言代码如下：

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

// 定义链表节点结构体
typedef struct Node {
    int data;
    struct Node* next;
} Node;

// 头插法插入节点
void insertAtHead(Node** headRef, int newData) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = newData;
    newNode->next = *headRef;
    *headRef = newNode;
}

// 尾插法插入节点
void insertAtTail(Node** headRef, int newData) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = newData;
    newNode->next = NULL;

    if (*headRef == NULL) {
        *headRef = newNode;
        return;
    }

    Node* lastNode = *headRef;
    while (lastNode->next != NULL) {
        lastNode = lastNode->next;
    }

    lastNode->next = newNode;
}

// 头删除节点
void deleteAtHead(Node** headRef) {
    if (*headRef == NULL) {
        return;
    }

    Node* tempNode = *headRef;
    *headRef = tempNode->next;
    free(tempNode);
}

// 尾删除节点
void deleteAtTail(Node** headRef) {
    if (*headRef == NULL) {
        return;
    }

    Node* lastNode = *headRef;
    Node* prevNode = NULL;
    while (lastNode->next != NULL) {
        prevNode = lastNode;
        lastNode = lastNode->next;
    }

    if (prevNode == NULL) {
        *headRef = NULL;
    } else {
        prevNode->next = NULL;
    }
    free(lastNode);
}

// 打印链表
void printList(Node* head) {
    Node* tempNode = head;
    while (tempNode != NULL) {
        printf("%d ", tempNode->data);
        tempNode = tempNode->next;
    }
    printf("\n");
}

int main() {
    Node* head = NULL;

    // 头插法插入节点
    insertAtHead(&head, 1);
    insertAtHead(&head, 2);
    insertAtHead(&head, 3);
    printf("After head insert: ");
    printList(head);

    // 头删除节点
    deleteAtHead(&head);
    printf("After head delete: ");
    printList(head);

    // 尾插法插入节点
    insertAtTail(&head, 4);
    insertAtTail(&head, 5);
    insertAtTail(&head, 6);
    printf("After tail insert: ");
    printList(head);

    // 尾删除节点
    deleteAtTail(&head);
    printf("After tail delete: ");
    printList(head);

    return 0;
}