链表中倒数第k个结点

Description：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 null;        ListNode start = new ListNode(0);        ListNode low = start;        ListNode fast = start;        low.next = head;                for (int i = 1; i <= k; i++) {            fast = fast.next;        }        boolean flag = false;        while (fast != null) {            fast = fast.next;            low = low.next;            flag = true;        }        if (flag)            return low;        return null;    }}