已有a,b两个链表，每个链表中的结点包括学号，成绩。要求把两个链表合并，按学号升序排列。

#include <stdio.h>
#include <stdlib.h>
#define LEN sizeof(struct student)
#define NULL 0
int n=0;
struct student {
int num;
char name[10];
struct student *next;

};

struct student *creat(void){                        //创建链表函数

struct student *head,*p1,*p2;
p1=p2=(struct student *)malloc(LEN);
head=NULL;
scanf("%d %s",&p1->num,p1->name);

while(p1->num!=0){
n++;
if(n==1){head=p1;}
else p2->next=p1;
p2=p1;
p1=(struct student *)malloc(LEN);
scanf("%d %s",&p1->num,p1->name);

}
p2->next=NULL;
n=0;
return head;

}

struct student *ronghe(struct student *p1,struct student *p2){   //链表合并函数

struct student *p=p1;

while(p1->next!=NULL) p1=p1->next;
p1->next=p2;

return p;
}

void paixu(struct student *p){                                  //链表排序函数
char tname[20];
int tnum,k=0,i=1;

struct student *p1;
p1=p;
while(i!=0)
{
while(p1->next!=NULL){
if(p1->num>p1->next->num)  {
tnum=p1->num;
p1->num=p1->next->num;
p1->next->num=tnum;

strcpy(tname,p1->name);
strcpy(p1->name,p1->next->name);
strcpy(p1->next->name,tname);
k++;
}
p1=p1->next;
}
p1=p;
if(k>0){k=0;}
else i=0;

}

}

void print(struct student *p){                                  //打印链接函数

while(p!=NULL){
printf("%d %s\n",p->num,p->name);
p=p->next;
}
}

int main()
{
struct student *p1=creat();
struct student *p2=creat();
struct student *p=ronghe(p1,p2);
paixu(p);
print(p);

}