题解 | #从上往下打印二叉树#
从上往下打印二叉树
https://www.nowcoder.com/practice/7fe2212963db4790b57431d9ed259701
import java.util.*; import java.util.ArrayList; /** public class TreeNode { int val = 0; TreeNode left = null; TreeNode right = null; public TreeNode(int val) { this.val = val; } } */ /** */ public class Solution { public ArrayList<Integer> PrintFromTopToBottom(TreeNode root) { ArrayList<Integer> result = new ArrayList<>(); if(root == null){ return result; } Queue<TreeNode> queue = new ArrayDeque<TreeNode>(); queue.offer(root); while(!queue.isEmpty()){ TreeNode curNode = queue.poll(); result.add(curNode.val); if(curNode.left != null){ queue.offer(curNode.left); } if(curNode.right != null){ queue.offer(curNode.right); } } return result; } }
今天的最后一题,冲冲冲