链表中倒数第k个节点

/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
import java.util.Stack;
public class Solution {
    public ListNode FindKthToTail(ListNode head,int k) {
        if (k <= 0) {
            return null;
        }
        Stack<ListNode> stack = new Stack();
        ListNode point = head;
        while (null != point){
            stack.push(point);
            point = point.next;
        }
        if (k > stack.size()){
            return null;
        }
        while(0 != k--){
            point = stack.pop();
        }
        return point;
    }
}

/*
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 (k <= 0) {
            return null;
        }
        ListNode refrence = head;
        ListNode point = null;
        int i = 1;
        while (null != refrence) {
            if (i == k) {
                point = head;
            } else if (i > k){
                point = point.next;
            }
            refrence = refrence.next;
            i++;
        }
        return point;
    }
}