c语言最经典地链表

＃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");

}

}

 

}