c链表结点的删除和添加

 #include<stdio.h>
 #include<stdlib.h>
 typedef char datetype;/*定义新的数据类型名*/
 typedef struct node
 {
     datetype date;
     struct node *next;
 }listnode;
 typedef listnode *linklist;
 int delete(linklist h,int num)/*删除结点*/
 {
     linklist p=h;
     listnode *q=NULL;
     int i=num;
     int n=;
     while(n<i)/*寻找删除位置*/
     {
         q=p;/*该结点和前后两个结点*/
         p=p->next;
         n++;
     }
     if(p==NULL)/*该结点不存在*/
         printf("No Found Node!");
     else
     {
         q->next=p->next;
         free(p);
     }
 }

 void output(linklist head)/*链表遍历*/
 {
     linklist p=head;
     while(p!=NULL)
     {
         printf("%c",p->date);
         p=p->next;
     }
 }
 int rear_creat(linklist head,int index0,int m)/*插入新结点，链表头，结点位置，结点date*/
 {
     linklist k,g;
     int i=index0,n;
     k=head;
     n=;
     while(n<i)/*寻找结点位置*/
     {
         n++;
         k=k->next;
     }
     g=(listnode *)malloc(sizeof(listnode));
     g->next=k->next;
     g->date=m;
     k->next=g;
 }
 int main()
 {
     char ch;
     int index,index0;
     char m;
     linklist head=NULL;
     listnode *p,*r;
     ch=getchar();
     while(ch!='\n')
     {
         p=(listnode *)malloc(sizeof(listnode));
         p->date=ch;
         if(head==NULL)
             head=p;
         else
             r->next=p;
         r=p;
         ch=getchar();
     }
     output(head);
     printf("\ndelete a node:\n");
     scanf("%d",&index);
     if(index==)
         head=head->next;
     else
         delete(head,index);
     output(head);

     printf("\ncreat a node:\n");
     scanf("%d%c",&index0,&m);
     rear_creat(head,index0,m);
     output(head);
     return ;
 }

 #include<stdio.h>/*尾插法*/
 #include<stdlib.h>
 typedef char datetype;
 typedef struct node
 {
     datetype date;
     struct node *next;
 }listnode;

 typedef listnode *linklist;
 linklist r=NULL,head=NULL;

 void rear_creat(datetype ch)
 {
     linklist p=NULL;
     p=(listnode *)malloc(sizeof(listnode));
     p->date=ch;
     if(head==NULL)
     {
         head=p;
     }
     else
     {
         r->next=p;
     }
     r=p;
 }
 void output(linklist head)
 {
     while(head!=NULL)
     {
         printf("%c ",head->date);
         head=head->next;
     }

 }
 void insert_rear(int index,int num)
 {
     listnode *p=NULL,*u;
     u=head;
     int n=;
     p=(listnode *)malloc(sizeof(listnode));
     p->date=index;
     while(num>n)
     {
         u=u->next;
         n++;
     }
     p->next=u->next;
     u->next=p;
 }
 void delete(int num)
 {
     int n=;
     linklist p=head,q;
     while(num>n)
     {
         n++;
         q=p;
         p=p->next;
     }
     q->next=p->next;
 }

 int main()
 {
     datetype index,ch;
     int num;
     ch=getchar();
     while(ch!='\n')
     {
         rear_creat(ch);
         ch=getchar();
     }
     output(head);
     scanf("%c%d",&index,&num);
     insert_rear(index,num);
     output(head);
     scanf("%d",&num);
     delete(num);
     output(head);
 }