226. Invert Binary Tree

문제

https://leetcode.com/problems/invert-binary-tree/description/

풀이

class Solution {
    public TreeNode invertTree(TreeNode root) {
        if(root == null) {
            return null;
        }

        TreeNode left = root.left;
        TreeNode right = root.right;

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

        return root;
    }
}

• root 노드에서 in-place 정렬