Arup's Kattis Problem List
One of my favorite websites to submit problems to is Kattis. I love the
interface and it's really fun to see your checkmarks for each test case.
One thing I don't like about Kattis is that the problems are not sorted
very nicely, particularly by category. Often times, when students begin
practicing for contests, they want to hone in on a specific area and do
several problems just in that area. This is quite different than a real
contest where you get problems that could be solvable by any technique.
To that end, what I've done is start compiling a list of Kattis problems,
where I identify the category and give it a rating from 1 - 9. To learn
more about my rating system go here.
Recently, I have found that my original list might be difficult to use for
students who are just getting started, particularly at the high school
level. At that level, it's important to get more repetition with problems
that don't require a ton of specified algorithmic knowledge. To that end,
I've started creating a beginner list, also linked above. (I've used most
of my 1s and 2s from the original list, but also added some new problems
here.) Right now, I've only got some 1s, 2s and 3s. I've focused on
picking problems that involve similar techniques. Key items I would like
beginning students to focus on: mathematical problem solving, base
conversion/use of mod, use of built in data structures (lists, sets, trees,
priority queue), custom sorting and standard greedy patterns. These topics
show up quite a bit in the problems I've picked so far. Also, I've tried
to roughly order themby difficulty, even within the difficulty ranges, as
best as possible. Right now there are only 60 problems, but I hope to grow
this sometime.
Some may disagree with my ratings and even my categorization, but my hope
is that for some students, this will help provide some practice problems
that reasonably fit within the category and difficulty of practice that
students are looking for.
The files (linked above) are spreadsheets. You may sort it any way
you like. Currently, the college one is sorted by category, and by
difficulty within each category. The high school one is sorted by
difficulty only.
Arup