diff --git a/src/s0226_invert_binary_tree.cpp b/src/s0226_invert_binary_tree.cpp
new file mode 100644
index 0000000..9b44b3b
--- /dev/null
+++ b/src/s0226_invert_binary_tree.cpp
@@ -0,0 +1,9 @@
+#include "s0226_invert_binary_tree.hpp"
+
+TreeNode *S0226::invertTree(TreeNode *root) {
+  if (root == nullptr) return nullptr;
+  TreeNode *tmp = root->left;
+  root->left = invertTree(root->right);
+  root->right = invertTree(tmp);
+  return root;
+}