题解 | #链表中倒数最后k个结点#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param pHead ListNode类 
 * @param k int整型 
 * @return ListNode类
 */
struct ListNode* FindKthToTail(struct ListNode* pHead, int k ) {
    // write code here
  struct ListNode*slow = pHead;
  struct ListNode* fast = pHead;
  struct ListNode *cur = pHead;
  int count = 0;
  while(cur)
  {
    cur = cur->next;
    count++;//计算节点的个数
  }
  if(count < k)//判断k的值是否大于节点的个数
  return NULL;
  while(k-- && fast)//找到slow与fast之间的差距
  {
    fast = fast->next;
  }
  //if(fast == NULL)
 // return NULL;
  while(fast)
  {
    fast = fast->next;
    slow = slow->next;
  }
  return slow;
}