solve invert binary tree

Author: sora0319

invert-binary-tree/sora0319.java

@@ -0,0 +1,15 @@
+public class Solution {
+    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;
+    }
+}