package question;


import java.util.ArrayList;
import java.util.List;

/*
 @author: Roderland
 @create: 2020年09月23日---12:52
*/
public class Question637 {
 public TreeNode mergeTrees(TreeNode t1, TreeNode t2) {
 if (t1!=null||t2!=null) {
 TreeNode treeNode;
 if (t1!=null&&t2!=null) {
 treeNode = new TreeNode(t1.val + t2.val);
 treeNode.left = mergeTrees(t1.left, t2.left);
 treeNode.right = mergeTrees(t1.right, t2.right);
 } else if (t1!=null) {
 treeNode = new TreeNode(t1.val);
 treeNode.left = mergeTrees(t1.left, null);
 treeNode.right = mergeTrees(t1.right, null);
 } else {
 treeNode = new TreeNode(t2.val);
 treeNode.left = mergeTrees(t2.left, null);
 treeNode.right = mergeTrees(t2.right, null);
 }
 return treeNode;
 }
 return null;
 }

 public List<Double> averageOfLevels2(TreeNode root) {
 if (root == null) return new ArrayList<>(0);
 List<TreeNode> nodeList = new ArrayList<>(2);
 List<Double> list = new ArrayList<>();
 nodeList.add(root);
 list.add(root.val+0d);
 while (true) {
 List<TreeNode> newNodeList = new ArrayList<>();
 Double sum = 0d;
 for (TreeNode treeNode : nodeList) {
 if (treeNode.left != null) {
 newNodeList.add(treeNode.left);
 sum+=treeNode.left.val;
 }
 if (treeNode.right != null) {
 newNodeList.add(treeNode.right);
 sum+=treeNode.right.val;
 }
 }
 if (newNodeList.isEmpty()) break;
 list.add(sum/newNodeList.size());
 nodeList = newNodeList;
 }
 return list;
 }
}