int InsertLinkList(LinkList *H, int i, DataType x)
/*在有頭結(jié)點(diǎn)的線性鏈表H中第i個(gè)位置前插入元素x*/
{
    LinkList *p;
    LinkList *s;
    int j = 0;
    p = H;
    while (p && j<i-1)
    {
        p = p->next;
        j++;
    }/*循環(huán)直到p指向第i-1個(gè)元素*/
    if (!p)
        return -1;/*i大于表長加1*/
    s = (LinkList *)malloc(sizeof(LinkList));
    s->data = x;
    s->next = p->next;/*插入數(shù)據(jù)元素x*/
    p->next = s;
    return 1;
}

s->next = H->next; H->next = s;

LinkList *CreateLinkList_front()
{
    LinkList *H;/*H表示頭結(jié)點(diǎn)*/
    LinkList *s;
    char x;/*設(shè)數(shù)據(jù)元素的類型為char*/
    H = (LinkList *)malloc(sizeof(LinkList));/*為頭結(jié)點(diǎn)申請內(nèi)存空間*/
    H->next = NULL;
    scanf(" %c", &x);
    while (x!=flag)/*flag為結(jié)束創(chuàng)建過程的標(biāo)志，如'#'等*/
    {
        s = (LinkList *)malloc(sizeof(LinkList));
        s->data = x;
        s->next = H->next;
        H->next = s;
        scanf(" %c", &x);
    }
    return H;
}

LinkList *CreateLinkList_rear()
{
    LinkList *H;
    DataType x;/*設(shè)DataType為數(shù)據(jù)元素的類型*/
    int i = 1;
    H = (LinkList *)malloc(sizeof(LinkList));
    H->next = NULL;
    scanf(&x);/*讀入數(shù)據(jù)元素的值*/
    while (x!=flag)
    {
        InsertLinkList(H, i, x);/*調(diào)用插入算法*/
        i++;
        scanf(&x);
    }
    return H;
}

LinkList *CreateLinkList_rear()
{
    LinkList *H, *p, *s;
    DataType x;/*設(shè)DataType為數(shù)據(jù)元素的類型*/
    H = (LinkList *)malloc(sizeof(LinkList));
    H->next = NULL;
    scanf(&x);/*讀入數(shù)據(jù)元素的值*/
    p = H;
    while (x!=flag)
    {
        s = (LinkList *)malloc(sizeof(LinkList));
        s->data = x;
        s->next = NULL;
        p->next = s;
        p = p->next;
        scanf(&x);
    }
    return H;
}

p->next = p->next->next;

int DeleteLinkList(LinkList *H, int i)
/*在有頭結(jié)點(diǎn)的線性鏈表H中刪除第i個(gè)元素*/
{
    LinkList *p;
    LinkList *q;
    int j = 0;
    p = H;
    while (p->next && j<i-1)
    {
        p = p->next;
        j++;
    }/*循環(huán)直到p指向第i-1個(gè)元素*/
    if (!(p->next))
        return -1;/*刪除節(jié)點(diǎn)不合法*/
    q = p->next;
    p->next = q->next;/*刪除第i個(gè)數(shù)據(jù)元素*/
    free(q);/*釋放第i個(gè)數(shù)據(jù)元素所占內(nèi)存*/
    return 1;
}

LinkList *SearchLinkList(LinkList *H, DataType x)
/*在線性鏈表H中查找值為x的結(jié)點(diǎn)，找到后返回其指針，否則返回空*/
{
    LinkList *p = H->next;/*p指向線性鏈表的第一個(gè)數(shù)據(jù)元素*/
    while (p!=NULL && p->data!=x)
        p = p->next;
    return p;
}

int SearchLinkList(LinkList *H, DataType x)
/*在線性鏈表H中查找值為x的結(jié)點(diǎn)，找到后返回其在鏈表中的位序，否則返回-1*/
{
    LinkList *p = H->next;/*p指向線性鏈表的第一個(gè)數(shù)據(jù)元素*/
    int i = 1;
    while (p!=NULL && p->data!=x)
    {
        p = p->next;
        i++;
    }
    if (p != NULL)
        return i;
    else
        return -1;
}

int LinkListLength(LinkList *H)
{
    LinkList *p = H;/*p指向頭結(jié)點(diǎn)*/
    int n = 0;
    while (p->next)
    {
        p = p->next;
        n++;
    }/*p所指的是第n個(gè)結(jié)點(diǎn)*/
    return n;
}