帮我看看这程序  哪里错了 为什么到调用函数那里就不能再执行了呢？？？？？？


#include"stdio.h"
#include"malloc.h"
#include"string.h"
#define NULL 0
#define STU_TYPE struct student
#define STU_SIZE sizeof(STU_TYPE)
STU_TYPE{
        long num;
        char name[20];
        char sex;
        STU_TYPE *next;
    };
int n=0;
void main(){
    void print(STU_TYPE *);
    STU_TYPE *head,*p1,*p2;
    
    p2=p1=(STU_TYPE*)malloc(STU_SIZE);
    head=p1;
    scanf("%ld%s%s",&p1->num,p1->name,&p1->sex);
    while(p1->num!=0)
        {
            n++;
            if(n==1) head=p1;
            else
                p2->next=p1;
                p2=p1;
            p1=(STU_TYPE*)malloc(STU_SIZE);
        
            scanf("%ld%s%s",&p1->num,p1->name,&p1->sex);
        
    }
    p2->next=NULL;

        print(head);
}
    
    void print(STU_TYPE *head)
        {
            STU_TYPE *q;
            q = head;
            if (q != NULL)
                while (q -> next != NULL)
                    {
                        printf("%ld%s%s\n",q->num,q->name,q->sex);
                        q++;
                }
                else
                    printf("void list!");
                }