I'm reading a paper on my phone in bed and see this problem:

Convolving a list with itself. Given a list [x1, x2, ..., xn−1, xn], where n is unknown, construct [(x1, xn), (x2, xn−1), ..., (xn−1, x2), (xn, x1)] in n recursive calls.

And I am able to switch apps and solve it right on my phone, without needing to get out of bed.

I do have to put up with some klunky syntax, though: https://akkartik.itch.io/carousel

Comments gratefully appreciated. Please send them to me by any method of your choice and I'll include them here.