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 = ;
     if(phead == NULL || k == )
         return NULL;

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