用codeblocks编写c++程序出现输出中文乱码问题

（总结问题来源和从网上找到的方法）

程序如上，并无语法问题但是编译是中文出现乱码，而且codeblock右下角会出现：

The saved document contained characters which were illegal in the selected encoding.
The file’s encoding has been changed to UTF-8 to prevent you from losing data.

解决方法:找到工具栏上 Setting->Editor->Encoding setting ->Encoding：using this encoding->勾选As default encoding
再关闭重启即可。