/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
List list;
public List inorderTraversal(TreeNode root) {
list = new ArrayList<>();
inorder(root);
return list;
}
public void inorder(TreeNode tr) {
if (tr != null) {
if (tr.left != null)
inorder(tr.left);
list.add(tr.val);
if (tr.right != null)
inorder(tr.right);
}
}
}