226 Invert Binary Tree

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public TreeNode invertTree(TreeNode root) {
        if(root == null) return null;
TreeNode left = root.left;
TreeNode right = root.right;

TreeNode tl = invertTree(left);
TreeNode tr = invertTree(right);

root.left = tr;
root.right = tl;

return root;
        
    }
}