make comment tidy
diff --git a/cpp/README.md b/cpp/README.md
index abd737a..b742c4d 100644
--- a/cpp/README.md
+++ b/cpp/README.md
@@ -1,21 +1,21 @@
 <!--
 
-​    Licensed to the Apache Software Foundation (ASF) under one
-​    or more contributor license agreements.  See the NOTICE file
-​    distributed with this work for additional information
-​    regarding copyright ownership.  The ASF licenses this file
-​    to you under the Apache License, Version 2.0 (the
-​    "License"); you may not use this file except in compliance
-​    with the License.  You may obtain a copy of the License at
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
 
-​        http://www.apache.org/licenses/LICENSE-2.0
+        http://www.apache.org/licenses/LICENSE-2.0
 
-​    Unless required by applicable law or agreed to in writing,
-​    software distributed under the License is distributed on an
-​    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-​    KIND, either express or implied.  See the License for the
-​    specific language governing permissions and limitations
-​    under the License.
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
 
 -->
 
diff --git a/cpp/examples/README.md b/cpp/examples/README.md
index 7b20d5f..9772873 100644
--- a/cpp/examples/README.md
+++ b/cpp/examples/README.md
@@ -1,21 +1,21 @@
 <!--
 
-​    Licensed to the Apache Software Foundation (ASF) under one
-​    or more contributor license agreements.  See the NOTICE file
-​    distributed with this work for additional information
-​    regarding copyright ownership.  The ASF licenses this file
-​    to you under the Apache License, Version 2.0 (the
-​    "License"); you may not use this file except in compliance
-​    with the License.  You may obtain a copy of the License at
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
 
-​        http://www.apache.org/licenses/LICENSE-2.0
+        http://www.apache.org/licenses/LICENSE-2.0
 
-​    Unless required by applicable law or agreed to in writing,
-​    software distributed under the License is distributed on an
-​    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-​    KIND, either express or implied.  See the License for the
-​    specific language governing permissions and limitations
-​    under the License.
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
 
 -->
 
diff --git a/cpp/examples/cpp_examples/demo_read.cpp b/cpp/examples/cpp_examples/demo_read.cpp
index 4951e8c..8ce775d 100644
--- a/cpp/examples/cpp_examples/demo_read.cpp
+++ b/cpp/examples/cpp_examples/demo_read.cpp
@@ -16,6 +16,7 @@
  * specific language governing permissions and limitations
  * under the License.
  */
+
 #include <iostream>
 #include <string>
 #include <vector>
diff --git a/cpp/examples/cpp_examples/demo_write.cpp b/cpp/examples/cpp_examples/demo_write.cpp
index 594309b..dcb5c7b 100644
--- a/cpp/examples/cpp_examples/demo_write.cpp
+++ b/cpp/examples/cpp_examples/demo_write.cpp
@@ -17,12 +17,8 @@
  * under the License.
  */
 
-#include <cwrapper/tsfile_cwrapper.h>
-#include <time.h>
 #include <writer/tsfile_table_writer.h>
 
-#include <iostream>
-#include <random>
 #include <string>
 
 #include "cpp_examples.h"