复习-JZ60 把二叉树打印成多行

import java.util.*;


/*
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
public class Solution {
    ArrayList<ArrayList<Integer> > Print(TreeNode pRoot) {

        Queue<TreeNode> que = new LinkedList<TreeNode>();
        ArrayList<ArrayList<Integer>> res = new ArrayList<>();
        if(pRoot==null) return res;

        que.offer(pRoot);
        while(!que.isEmpty()){
            int n = que.size();
            ArrayList<Integer> temp = new ArrayList<>();
            for(int i=0;i<n;i++){
                TreeNode cur = que.poll();
                temp.add(cur.val);
                if(cur.left!=null) que.offer(cur.left);
                if(cur.right!=null) que.offer(cur.right);
            }
            res.add(temp);
        }
        return res;
    }
}