Writing Interactors and Checkers on Codechef

I’m having trouble writing interactors on codechef platform. Can anyone who has written an interactor for a codechef problem show a sample of an interactor? Thanks.

UPD : I’m also facing problems on writing a working checker.

UPD : For writing an interactor, I used #include “spoj_interactive.h”, but even including this header throws errors about some variables being already defined.

What is an interactor?

Look at the interactive problems. You need to write a program (for the judge side) that can read the participant’s input and output accordingly.

Oh like the RESTPERM at the last lunchtime.

Yes, that’s one example of an interactive problem.