【LeetCode程序员面试金典】面试题 02.02. Kth Node From End of List LCCI

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public int kthToLast(ListNode head, int k) {
        ListNode first = head, second = head;
        for(int i=0;i<k;i++){
            first=first.next;
        }
        while(first!=null){
            first = first.next;
            second = second.next;
        }
        return second.val;
    }
}