用c语言写一段完整的代码 用插入法建立带头结点的单循环链表，实现单循环链表的初始化、求数据元素个数、插入、删除、取数据元素等操作。

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

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

// 初始化链表
Node* createList() {
    Node* head = (Node*)malloc(sizeof(Node));
    if (!head) {
        printf("Memory allocation failed.\n");
        return NULL;
    }
    head->data = 0; // 默认头节点值为0
    head->next = head; // 链表形成循环
    return head;
}

// 求链表元素个数
int size(Node* head) {
    int count = 0;
    Node* temp = head;
    while (temp != head->next) {
        count++;
        temp = temp->next;
    }
    return count + 1; // 包含头节点
}

// 插入元素到链表
void insert(Node** head, int value) {
    Node* newNode = (Node*)malloc(sizeof(Node));
    if (!newNode) {
        printf("Memory allocation failed.\n");
        return;
    }
    newNode->data = value;
    newNode->next = (*head)->next;
    (*head)->next = newNode; // 新节点连接到尾部并形成循环
}

// 删除指定位置的元素
void delete(Node** head, int index) {
    if (index <= 0 || !(*head)) {
        printf("Invalid index or empty list.\n");
        return;
    }

    Node* current = *head;
    Node* previous = NULL;
    for (int i = 1; i < index && current != head->next; ++i) {
        previous = current;
        current = current->next;
    }

    if (current == head->next) { // 如果索引越界，不做处理
        printf("Element not found.\n");
    } else {
        if (previous) {
            previous->next = current->next;
        } else {
            *head = current->next; // 如果要删除的是头节点，更新头指针
        }
        free(current);
    }
}

// 取数据元素
int getData(Node* head, int index) {
    if (index <= 0 || !head || head->next == head) {
        printf("Invalid index or empty list.\n");
        return -1; // 返回无效数据
    }

    Node* current = head;
    for (int i = 0; i < index; ++i) {
        if (current == head->next) {
            printf("Element not found.\n");
            return -1;
        }
        current = current->next;
    }

    return current->data;
}

int main() {
    Node* list = createList();
    
    // 执行其他操作示例
    insert(&list, 5);
    printf("List size after insertion: %d\n", size(list));

    int removedData = getData(list, 1);
    if (removedData != -1) {
        delete(&list, 1); // 删除第1个元素
        printf("After deletion: Size is %d and data at position 1 is %d\n", size(list), removedData);
    }

    return 0;
}