程序代码：

void sort(PSC phead)        //链表的排序
{    
    PSC p1, p2,p3,p4,p;
    p1=phead;
int td;
char tc[50];
p2 = p1->pnext;
p3 = (PSC)malloc(sizeof(SC));
while(p1->pnext != NULL)
{
p1 = p1->pnext;
}
p4 = p1;
p1->pnext = p3;
p3->pnext = NULL;

p1=phead;
     do
    {
p2 = p1;
while(p2->pnext != NULL)
{
if(p1->score < p2->score)
{
td = p1->score;
p1->score = p2->score;
p2->score = td;
strcpy(tc, p1->name);
strcpy(p1->name, p2->name);
strcpy(p2->name, tc);
}
p2 = p2->pnext;
}
p1 = p1->pnext;
    }while(p1->pnext != NULL);
p4->pnext = NULL;
free(p3);

p = phead;   // 输出
printf("\n\t\t排序后：\n");
while(p!= NULL)
{
printf("\t\t\t%s\t\t%d\n", p->name, p->score);
p = p->pnext;
}
system("pause");
}

void  exit0(PSC phead)
{
PSC p1, p2;    
p1=phead;
while( p1!=NULL)
{    p2=p1->pnext;
free(p1);
p1=p2;
}
}