题解 | #链表中倒数最后k个结点#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 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
     */
    public ListNode FindKthToTail (ListNode pHead, int k) {
        // write code here
      ListNode fast = null;
      ListNode slow = null;
      ListNode temp = pHead;

     for (int i = 0;i<k;i++){
          if(temp == null){
            return null;
          }
         fast = temp;
         temp = temp.next;

     }
        temp = pHead;
        while(fast != null){
            slow = temp;
            fast = fast.next;
            temp = temp.next;
        }
        pHead = slow;
        return pHead;
    }
}