leetcode-面试题22：链表中倒数第二个节点

题目描述：

 java：快慢指针：

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