单链表的插入、删除

代码

Status InsertList(LinkList head,DataType x,int i)
{
    ListNode *p;
    p = head;
    int j = 1;
    while(p->next&&j<i){
        p = p->next;
        ++j;
    }
    if(p == NULL)
    {
        printf("Position Error");
        return ERROR;
    }
    s =(LinkNode*)malloc(sizeof(ListNode));
    s->data = x;
    s->next =p->next;
    p->next =s;
    return OK;
}

代码

Status DeleteList(LinkList head,int i)
{
    ListNode *p,*r;
    p = head;
    int j =1;
    while(p->next&&j<i)
    {
        p = p->next;
        ++j;
    }
    if(p == NULL||p->next ==NULL||j>i)
    {
        printf("Position Error");
        return ERROR;
    }
    r = p->next;
    p->next = r->next;
    free(r);
    return OK;
}

引申 ：如何删除单链表的头元素？
代码

void RemoveHead(LinkList head)
{
    ListNode *p;
    p= head->next;
    head->next = p->next;
    free(p);
}