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=1;
    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=1;
    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!='
')
    {
        p=(listnode *)malloc(sizeof(listnode));
        p->date=ch;
        if(head==NULL)
            head=p;
        else
            r->next=p;
        r=p;
        ch=getchar();
    }
    output(head);
    printf("
delete a node:
");
    scanf("%d",&index);
    if(index==1)
        head=head->next;
    else
        delete(head,index);
    output(head);

    printf("
creat a node:
");
    scanf("%d%c",&index0,&m);
    rear_creat(head,index0,m);
    output(head);
    return 0;
}

#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=1;
    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=1;
    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!='
')
    {
        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);
}