The British Informatics Olympiad (BIO) is the UK's national computing challenge used to select students for the IOI, EGOI and WEOI. It is through this competition that I met most of my friends today. I feel privileged to have attended the finals twice, and as a result, represented the UK at the WEOI twice.
However, one issue I encountered during my first year of attempting this competition is the lack of helpful resources available online. There are a few YouTube video explanations, but for the vast majority of past problems from this competition, there are no editorials or model code.
That’s why I decided to create BIO Helper, a website dedicated to helping students prepare for both rounds of the competition by providing editorials and model code. With the help of many volunteers listed on the website (including, but not limited to, other BIO finalists), we now have a large proportion of Round 1 problems covered, along with a good number of Round 2 problems, with many more to come.
I want to share this site with as many people as possible so that more people can learn about competitive programming and find it easier to prepare for the BIO competition.
The website is relatively new, and we plan to add many features soon, including a grading system for Round 1. While there is publicly-available test data online, testing programs can be tedious, as it involves copying inputs, comparing outputs, and tallying points manually. Therefore, we plan to introduce a system where you can submit code, automatically receive your score, and see which test cases (if any) you failed. (Please note that in no way is this related to the official competition, during which participants will NOT be able to submit their code to be tested against any complete test data. This will just be a tool used for convenience during practice).
Finally, this project is open source, so if you find any bugs or have suggestions for improving the site, feel free to provide feedback by raising an issue on our GitHub.
Thank you for reading, and please don't forget to spread the word to those who you think may benefit from using this!
bo'ohw'o'wo'er!!!
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I'm a bit curious about the BIO R2 scoring rules in real contest.
The problem statements are not mentioning any subtask or partial score testcases. Is it revealed in actual contest, or the scoring still follow the old-fashioned way of number of passed testcases (maybe with hidden special property or size, requiring contestant to do their best in runtime efficiency)?
Also, do the problems have equal scores? Will easier problems have lower scores? Sometimes there will be another bonus problem, how will the problem be scored?
During the contest, there is a custom grader for BIO R2 problems. You are only allowed 5 submissions per problem. The feedback is also quite limited — here's an example:
Of course, many people ask what the difference between 'easy', 'medium', and 'hard' tests are, and there's no clear distinction, really. It's even possible that some 'medium' tests can have much higher constraints than some 'hard' tests. Sometimes test groups have different cases which your program might not have accounted for? But who knows, really.
Now for the scoring rules. Dr Forster, the team leader for the UK, repeatedly mentions that the number of full solutions is the most important criterion. All problems are worth the same amount, as well. So actually, even if you pass a higher % of tests than someone else, if you get fewer full solutions then it's viewed as less valuable.
Apparently, in the back there's some kind of hidden scoreboard which shows % of tests passed and number of full solutions, but it's not available for participants during or after the contest. In the two years I went to the finals, it was pretty easy for them to select the team because when ordered by full solves, the 4th person placed strictly higher than the 5th person. If there's a tie, one would assume at this point he might take into account the % of tests passed, and he's also mentioned that accuracy of submissions and clean code is also taken into account in this case. Basically, it's just discussed between the organisers and is up to them.
It's surprising to know that there is still a such black-boxed scoring rule and also contest feedback...
But at least they give 5 submissions.
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