c语言的链表

＃include"stdio.h"
＃include"malloc.h"
#define NULL 0
#define L sizeof(struct integer)
struct integer                           /*定义结构体*/
{
int num;
int zhengshu;
    struct integer *next;
};
int n;   //纪录链表的长度
struct integer *creat(void)             /*创建链表*/
{
    struct integer *head;
    struct integer *p1,*p2;
    n=0;
    p1=p2=(struct integer *)malloc(L);
    scanf("%d,%d",&p1->num,&p1->zhengshu);
    head=NULL;
    while(p1->num!=0)
{
n=n+1;
        if(n==1) head=p1;
        else p2->next=p1;
        p2=p1;
        p1=(struct integer *)malloc(L);
        scanf("%d,%d",&p1->num,&p1->zhengshu);
}
    p2->next=NULL;
    return(head);
}

void print(struct integer *head)    /*打印链表中的数据*/
{
    struct integer *p;
    printf("Now %d biaohao and zhengshu are :n",n);
    p=head;
    if(head!=NULL)
    do
     {printf("%d,%5.1dn",p->num,p->zhengshu);
      p=p->next;
     }while(p!=NULL);
}

int count(struct integer *head)   /*返回链表的长度*/
{
int i=0;
    struct integer *p;
p=head;
while(p!=NULL)
{
p=p->next;i++;
}
return i;
}

void *findnode(struct integer *head,int num)  /*查找链表中的第num个数据*/
{
int j=1;
struct integer *p;
/*if(head==NULL)
{
printf("n空链表，请先创建！n");
return;
}*/
p=head;
if(num>count(head)||num<=0)
{
printf("Input error! Please input againn");
}
else
{
while(p!=NULL && jnext;
}
printf("%d bianhao reprensts %dn",p->num,p->zhengshu);
printf("n");
}
return(head);
}


struct integer *del(struct integer *head,long num)  /*删除链表中的第num个数据*/
{
struct integer *p1,*p2;
    if(head==NULL)
{
printf("nList Null!n");
        return;
}
    p1=head;
    while(num!=p1->num && p1->next!=NULL)
{
        p2=p1;
        p1=p1->next;
}
    if(num==p1->num)
    {
        if(p1==head) head=p1->next;
        else p2->next=p1->next;
        printf("Delete: %dn",num);
        n=n-1;
    }
    else printf("%d not been fonnd!n",num);
    return(head);
}

struct integer *insert(struct integer *head,struct integer *stud)  /*插入数据*/
{
    struct integer *p0,*p1,*p2;
    p1=head;
    p0=stud;
    if(head==NULL)
{
head=p0;
        p0->next=NULL;
}
    else
{
while((p0->num>p1->num)&&(p1->next!=NULL))
{
p2=p1;
            p1=p1->next;
}
if(p0->num<=p1->num)
{
            if(head==p1)head=p0;
            else p2->next=p0;
            p0->next=p1;
}
        else
{
            p1->next=p0;
            p0->next=NULL;
}
}
    n=n+1;
    return(head);
}

main()  /*主功能函数*/
{
int a,b;
    struct integer *head,stu;
    int del_num,fin_num;
printf("1 to go on / 0 to exit:n");
scanf("%d",&a);
while(a!=0)
{
/*struct integer *head,stu;
        int del_num;*/
printf("1 creat 2 print 3 delete 4 insert 5 findonde 0 exitn");
/*菜单的实现*/
scanf("%d",&b);
switch(b)
{
case 1:
{
/*clrscr();*/
printf("Please Input bianhao and data:n");
printf("for example 1,90  0,0 to exit:n");
head=creat();
}break;
case 2:
{
/*clrscr();*/
print(head);
}break;
case 3:
{
/*clrscr();*/
    printf("nInput the deleted biaohao:");
    scanf("%d",&del_num);
    head=del(head,del_num);
}break;
        case 4:
{
/*clrscr();*/
                printf("nInput the inserted biaohao and zhengshu:");
                scanf("%d,%d",&stu.num,&stu.zhengshu);
                head=insert(head,&stu);
}break;
        case 5:
{
/*clrscr();*/
printf("Please Input the bianhao you want to find:");
scanf("%d",&fin_num);
head=findnode(head,fin_num);
}break;
case 0:
{
     return;
}break;
default:
printf("Input error! Please input againn");
}
}
 
}