N名学生的成绩已在主函数中放入一个带头节点的链表结构中，h指向链表的头节点。 请编写函数fun，它的功能是：求出平均分，由函数值返回

/N名学生的成绩已在主函数中放入一个带头节点的链表结构中，h指向链表的头节点。
请编写函数fun，它的功能是：求出平均分，由函数值返回/

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

struct Node
{
    int data;
    struct Node *next;
};
float fun(struct Node *h)
{
    int sum = 0;
    int count = 0;
    struct Node *current = h->next;
    while (current != NULL)
    {
        sum += current->data;
        count++;
        current = current->next;
    }
    if (count == 0)
    {
        return -1;
    }
    return (float)sum / count;
}

int main(void)
{
    int n=0;
    printf("please enter student number\n");
    scanf("%d",&n);
    struct Node *head = (struct Node *)malloc(sizeof(struct Node));
    head->next = NULL;
    for (int i = 0; i < n; i++)
    {
        struct Node *new_node = (struct Node *)malloc(sizeof(struct Node));
        printf("please enter %d student score\n",i+1);
        scanf("%d",&new_node->data);
        new_node->next = head->next;
        head->next = new_node;
    }
    float average = fun(head);
    printf("平均成绩为: %.2f\n", average);
    return 0;
}