找出单链表的倒数第K个（从1开始计数）结点的值

typedef struct Link
{
    int data;
    struct Link* next;
}NODE,*pNODE;

NODE  *searchK(NODE *phead, int k)
{
    pNODE pcur = phead, ppre = phead;
    int cnt = 0;
    if(phead == NULL || k == 0)
        return NULL;

    while(pcur != NULL)
    {
        ++cnt;
        if(cnt > k)
            ppre = ppre->next;
        pcur = pcur->next;
    }
    if(cnt < k)
        return NULL;
    else
        return ppre;
}