Changes to Input and Output

Until 2024, problems in the Australian Informatics Olympiad (AIO) and on ORAC involved reading input from a specified file and writing output to a specified file (e.g. addin.txt and addout.txt). Starting in 2025, AIO problems will require you to use standard input and standard output. If these terms are unfamiliar, don't worry—here's what they mean in practice:

• When running code on your own computer, your program will wait for you to enter the input (e.g., via the keyboard), rather than reading from a file.
• When running code on your own computer, the output will be displayed directly on the screen, rather than written to a file.

The way ORAC judges your code has not changed.

Luckily, using standard input and output is generally simpler than reading and writing to files. For example:

• In Python, you can use input() and print().
• In C++, you can use scanf() and printf(), or cin and cout.

To help you adjust, most (but not all) old problems have been updated to use the new method. However, older submissions in the Hall of Fame may still follow the file-based approach.

For a step-by-step guide to managing input and output in the new format, check out the Starter Set I Tutorials.