package LeetCode;

public class LeetCode226 {

    /// 226. Invert Binary Tree
    /// https://leetcode.com/problems/invert-binary-tree/description/
    /// : O(n), n
    /// : O(h), h

    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;

        TreeNode(int x) {
            val = x;
        }
    }

    public TreeNode invertTree(TreeNode root) {

        if (root == null)
            return null;

        // 
        TreeNode left = invertTree(root.left);
        TreeNode right = invertTree(root.right);

        // 
        root.left = right;
        root.right = left;

        return root;
    }
}