?c语言不知道数据个数，求平均值（单链表方式）

c语言不知道数据个数，求平均值（单链表方式）http://blog.csdn.net/czloveyeer/article/details/7930533

本人初学乍到，欢迎提出各种意见

#include
#include

typedef struct student
{
    float score;
    struct student *link;
}NODE;

void main()
{
    /*创建链表*/
    NODE *head,*p1,*p2,*p;
    int n = 0,i=0;
    int flag;/*标记是否继续输入，0为停止输入*/
    float average =0.00;

    p1=p2=(NODE *)malloc(sizeof(NODE));
    head = NULL;
    printf("Please input score:\n");
    scanf("%f",&p2->score);
    do
    {
        n++;
        if(n==1)
        {
            head = p1;
        }
        p1->link= p2;
        p1=p2;
        printf("Whether to continue(1.yes\t0.no):\n");
        scanf("%d",&flag);
        if(flag)
        {
            p2 =(NODE *)malloc(sizeof(NODE));
            printf("Please input score:\n");
            scanf("%f",&p2->score);
        }
    }while(flag != 0);
    p1->link = NULL;

    p=head;
    while(p!=NULL)
    {
        average+=p->score;
        p=p->link;
        i++;
    }
    printf("This is score:%.2f",average/i);
    getch();
}