Can you solve it? Would you get into Oxford?

This year's test paper is here: https://www.maths.ox.ac.uk/study-here/undergraduate-study/ma...

I was surprised and (as a math major) delighted to see these sorts of problems. There are a lot of standard topics tested in nonstandard ways on the math portion (integration via change of variables, asymptotic analysis, determinants to name a few). Questions that would be difficult to "teach-to-the-test" for. I personally would have found the computer science questions impossible at that tender age. The question in the article is a non-obvious greedy algorithm. Inside the test paper you'll see a question that basically "discovers" Floyd's cycle detection. I don't know if there is any equivalent of this for high schoolers in the US, or if it would even be possible.