从尾到头打印链表

 *    public class ListNode {
 *        int val;
 *        ListNode next = null;
 *
 *        ListNode(int val) {
 *            this.val = val;
 *        }
 *    }
 */
import java.util.ArrayList;
import java.util.Stack;
public class  {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        Stack<Integer> stack = new Stack<>();
        while(listNode!=null){
            stack.push(listNode.val);
            listNode = listNode.next;
        }
        ArrayList<Integer> list = new ArrayList<>();
        while(!stack.isEmpty()){
            list.add(stack.pop());
        }
        return list;
    }
}

import java.util.ArrayList;
public class  {
    ArrayList<Integer> list = new ArrayList<>();
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        if(listNode != null){
            this.printListFromTailToHead(listNode.next);
            list.add(listNode.val);
        }
        return list;
    }
}