JZ60 把二叉树打印成多行

https://www.nowcoder.com/practice/445c44d982d04483b04a54f298796288

这题和上一题是一样的

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) {
        ArrayList<ArrayList<Integer>> result = new ArrayList<>();
        if (pRoot == null) return result;
        Queue<TreeNode> queue = new LinkedList<>();
        queue.add(pRoot);
        while (!queue.isEmpty()) {
            int size = queue.size();
            ArrayList<Integer> list = new ArrayList<>();
            for(int i = 0; i < size; i++) {
                TreeNode node = queue.remove();
                list.add(node.val);
                if (node.left != null) queue.add(node.left);
                if (node.right != null) queue.add(node.right);
            }
            result.add(list);
        }
        return result;
    }
}