用c语言写一个单链表

在C语言中，我们可以创建一个简单的单链表结构。这里是一个基本的单向链表节点定义、链表结构以及一些常用操作的例子：

// 定义链表节点结构
typedef struct Node {
    int data;       // 节点数据
    struct Node* next;  // 指向下一个节点的指针
} Node;

// 创建链表
Node* createList() {
    Node* head = NULL;
    return head;
}

// 插入节点到链表头部
void insertAtHead(Node** head, int value) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = value;
    newNode->next = *head;
    *head = newNode;
}

// 在特定位置插入节点
void insertAtPosition(Node** head, int position, int value) {
    if (position <= 0) {
        printf("Invalid position\n");
        return;
    }
    Node* newNode = (Node*)malloc(sizeof(Node));
    newNode->data = value;
    newNode->next = *head;
    
    Node* current = *head;
    for (int i = 0; i < position - 1 && current != NULL; ++i) {
        current = current->next;
    }
    if (current == NULL) {
        printf("Insertion position beyond the list.\n");
        free(newNode);
        return;
    }
    newNode->next = current->next;
    current->next = newNode;
}

// 删除节点
void deleteNode(Node** head, int value) {
    if (*head == NULL) {
        return;
    }

    if ((*head)->data == value) {
        Node* temp = *head;
        *head = (*head)->next;
        free(temp);
        return;
    }

    Node* current = *head;
    while (current->next != NULL && current->next->data != value) {
        current = current->next;
    }
    if (current->next == NULL) {
        printf("Value not found in the list.\n");
        return;
    }
    Node* temp = current->next;
    current->next = current->next->next;
    free(temp);
}

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