It's difficult to test solutions to interactive problems during or after a contest. For non-interactive problems, I usually redirect input from a file. For interactive problems I have to type out input manually, since input depends on output. If the interaction is long, this can take time.↵
↵
A more automated way will require 2 more programs:↵
↵
1. A judge program with whom our solution will interact.↵
2. A program which connects `stdout` of solution to `stdin` of judge and `stdout` of judge to `stdin` of solution. I call this program a '[croupier](https://en.wikipedia.org/wiki/Croupier)'.↵
↵
The judge program will have to be written by the user each time since it's problem-specific. But the croupier is generic and can be reused.↵
↵
My implementation of the croupier, apart from connecting inputs and outputs of the two programs, also prints the output from each program so that it's easier to debug.↵
↵
You can find my implementation here:↵
https://github.com/sharmaeklavya2/croupier↵
↵
I wrote the croupier so that it could help me debug [problem:750F]. The croupier helped me find out many mistakes in my solution, but it seems like there are more, because I can't get my solution accepted. Here is the judge program I used for it: https://gist.github.com/sharmaeklavya2/fb9751ba0d9d5df883d4d29288db8315↵
↵
Update: There was a small bug in croupier because of which it sometimes printed output incorrectly. Thanks you [user:PikMike,2017-01-03] for reporting this. [user:PikMike,2017-01-03] also tested this program on Windows, which I couldn't do myself because I don't have Windows. You can find a detailed description of the bug here: https://github.com/sharmaeklavya2/croupier/commit/a2fcd82a52a83df71518dfec248271d752a55b66
↵
A more automated way will require 2 more programs:↵
↵
1. A judge program with whom our solution will interact.↵
2. A program which connects `stdout` of solution to `stdin` of judge and `stdout` of judge to `stdin` of solution. I call this program a '[croupier](https://en.wikipedia.org/wiki/Croupier)'.↵
↵
The judge program will have to be written by the user each time since it's problem-specific. But the croupier is generic and can be reused.↵
↵
My implementation of the croupier, apart from connecting inputs and outputs of the two programs, also prints the output from each program so that it's easier to debug.↵
↵
You can find my implementation here:↵
https://github.com/sharmaeklavya2/croupier↵
↵
I wrote the croupier so that it could help me debug [problem:750F]. The croupier helped me find out many mistakes in my solution, but it seems like there are more, because I can't get my solution accepted. Here is the judge program I used for it: https://gist.github.com/sharmaeklavya2/fb9751ba0d9d5df883d4d29288db8315↵
↵
Update: There was a small bug in croupier because of which it sometimes printed output incorrectly. Thanks you [user:PikMike,2017-01-03] for reporting this. [user:PikMike,2017-01-03] also tested this program on Windows, which I couldn't do myself because I don't have Windows. You can find a detailed description of the bug here: https://github.com/sharmaeklavya2/croupier/commit/a2fcd82a52a83df71518dfec248271d752a55b66
