#include "stdafx.h"

#include "stdio.h"
#define NULL 0
struct student
{
    long num;
    float score;
    struct student * next;
};
int main(int argc, char* argv[])
{
    struct student a,b,c,*head,*p;    
    a.num=99101;a.score=89.5;
    b.num=99103;b.score=90;
    c.num=99107;c.score=85;
    head=&a;
    a.next=&b;
    b.next=&c;
    c.next=NULL;
    p=head;
    do//逆顺序排序该如何排，将链头当链尾
    {
        printf("%ld%5.1f\n",p->num,p->score);
        p=p->next;
    }while(p!=NULL);
    
    return 0;
}

链表没学，可能有错：
#include <stdio.h>
#define NULL 0
struct student
{
    long num;
    float score;
    struct student *next;
};
int main()
{
    struct student a,b,c,*head,*p;
    a.num=99101;a.score=89.5;
    b.num=99103;b.score=90;
    c.num=99107;c.score=85;
    head=&a;
    a.next=&b;
    b.next=&c;
    c.next=&a;
    p=head;
    do
    {
        p=p->next;
        printf("%ld%5.1f\n",p->num,p->score);
    }while(p->next!=&b);

    return 0;
}

还是不对啊

用三个指针就行啦！