hover on the line showing error

left click on the bulb, it will take you to C/C++ configurations

Now change complier path to C:/MinGW64/bin/g++.exe

on the top u will see a link c_cpp_properties.json click on it

in c_cpp_properties.json "intelliSenseMode": "windows-gcc-x64"

This works well.

​

source: https://github.com/microsoft/vscode-cpptools/issues/5723