fal 0基础-全栈风控入门训练营
class OrderTraversal {
public List<Integer> middleOrderTraversalRecursion(TreeNode root) {
List<Integer> result = new ArrayList<>();
if (root.left != null) {
result.addAll(middleOrderTraversalRecursion(root.left));
}
result.add(root.val);
if (root.right != null) {
result.addAll(middleOrderTraversalRecursion(root.right));
}
return result;
}}
