226 Invert Binary Tree

Problem

226 Invert Binary Tree

Solution

To invert a tree, just invert its left subtree and right subtree and then swap these two subtrees, another good example of recursion.

Code

public class Solution {
    public TreeNode invertTree(TreeNode root) {
        if (root != null) {
            TreeNode left = invertTree(root.right);
            TreeNode right = invertTree(root.left);
            root.left = left;
            root.right = right;
        }
        return root;
    }
}