剑指offer【13】- 链表中倒数第k个结点

输入一个链表，输出该链表中倒数第k个结点。

 /*

 public class ListNode {

     int val;

     ListNode next = null;

     ListNode(int val) {

         this.val = val;

     }

 }*/

 public class Solution {

     public ListNode FindKthToTail(ListNode head,int k) {

         if(head == null){

             return head;

         }

         int count = 0;

         ListNode list = head;

         while(list != null){

             count++;

             list = list.next;

         }

         if(k > count){

             return null;

         }

         ListNode node = head;

         for(int i = 0; i < count -k; i++){

             node = node.next;

         }

         return node;

     }

 }