import java.util.ArrayList;/*public class TreeNode {    int val = 0;    TreeNode left = null;    TreeNode right = null;    public TreeNode(int val) {        this.val = val;    }}*/import java.util.*;public class Solution {    ArrayList
     
      
        > Print(TreeNode pRoot) {        ArrayList
       
        
         > arrayList = new ArrayList
         
          
           >(); if(pRoot == null){ return arrayList; } Queue
           
             q1 = new LinkedList
            
             (); q1.add(pRoot); Queue
             
               q2 = new LinkedList
              
               (); while(!q1.isEmpty() || !q2.isEmpty()){ if(!q1.isEmpty()){ ArrayList
               
                 list = new ArrayList
                
                 (); while(!q1.isEmpty()){ TreeNode node = q1.poll(); list.add(node.val); if(node.left != null){ q2.add(node.left); } if(node.right != null){ q2.add(node.right); } } arrayList.add(list); }else{ ArrayList
                 
                   list = new ArrayList
                  
                   (); while(!q2.isEmpty()){ TreeNode node = q2.poll(); list.add(node.val); if(node.left != null){ q1.add(node.left); } if(node.right != null){ q1.add(node.right); } } arrayList.add(list); } } return arrayList; } }