If you are getting this error while running c++ code in vs code using 
code runner then follow below instructions :
This error might occur because you are using bash as your dafault terminal in 
visual studio code. So just set cmd(command prompt) as your default terminal 
in visual studio code and it should fix it.
To change default terminal :- 
  Press CTRL+Shift+P / ⇧⌘P and search for terminal select default shell