7-2 成绩大于等于某值的学生信息输出

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct stu * list;
struct stu{
    int num,score;
    char name[20];
    struct stu * next;
};
list create666(){
    list head,p,tail;
    head=NULL;
    int num,score;
    char name[20];
    scanf("%d",&num);
    scanf("%s",name);
    scanf("%d",&score);
    while(1){
        p=(list)malloc(sizeof(struct stu));
        scanf("%d",&num);
        if(num==0)
        break;               //这一步一定要用while(1)而不用书上的最后加scanf 因为最后会在缓冲区留下无用的数  
        p->num=num;				//影响后续输入min
        scanf("%s",p->name);
        scanf("%d",&p->score);
        p->next=NULL;
        if(head==NULL)
        head=p;
        else
        tail->next=p;
        tail=p;
        
    }
    return head;
}
list delete666(list head,int min){
    list p1,p2;
    while(head!=NULL&&head->score<min){
        p2=head;
    head=head->next;
    free(p2);
    }
    if(head==NULL)
    return NULL;
    p1=head;
    p2=head->next;
    while(p2!=NULL){
        if(p2->score<min){
            p1->next=p2->next;
            free(p2);
        }
        else
        p1=p2;
        p2=p1->next;
    }
    return head;
}
void print666(list head){
    list p;
    for(p=head;p!=NULL;p=p->next)
    printf("%d %s %d\n",p->num,p->name,p->score);
}
int main(){
    list head;
    head=create666();
    int min;
    scanf("%d",&min);
    head=delete666(head,min);
    print666(head);
    return 0;
}