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;

     }
 }