It would be nice to have a CODEFORCES environment variable, to allow our programs to print debug output selectively.
Currently I use my own variable to control debug output, but have to turn it off when submitting to CF. For difficult problems where I submit many times (during practice), it'd be nice to not have to turn that variable on, off, on, off, repeatedly. So some mechanism for the program to detect it is running on CF server, would be great.
Thanks for the nice platform and great problems.
Its use?