How do interactive problems work? Just as in non-interactive problems, you will receive input from stdin and print output to stdout. Our system will do the job of directing your output stream to the judge's input stream, and pointing the judge's output stream to your input stream. However, every time you output data, *you must flush your output buffer*, as explained below.
------------------- The reason why it is not working with *printf*, is because *STDOUT* is a buffered stream and it doesn't get flushed until the buffer is full or you manually triggered a flush. Without flushing the stream, the other program will not receive your data and therefore cannot send more data to your program. And your program wants to read the response and hence causes a deadlock. It was like your postman is holding your mail and waiting for more mail to come in (because he wants to send all mails in a batch) and you are waiting for the response that never comes. To solve this, simply flush your stream (like asking your postman to deliver your mail without waiting for more mails) The reason why *cout* would work is because whenever a *std::endl* is sent to the stream, it also triggered a flush so you don't have to manually do that. In other word, the following code will also fail for the same reason. *cout << something << '\n';* -- You received this message because you are subscribed to the Google Groups "Google Code Jam" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-code+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/google-code/1efcb358-48a8-4939-9380-ff2327b3d1c2%40googlegroups.com.
