Our solution for problem B was an attempt to generalize Fermat Little Theorem over polynomials, but we still don't have any proof about why it works?

Has anybody got WA20 in L? What can be the reason of it?

Editorial

F: if $$$s_b > s_p$$$ you can always win (by throwing far enough)
if $$$s_b = s_p$$$ you can always win, unless opponent is between you and your teammate
The main case is $$$s_b < s_p$$$. Draw a Perpendicular Bisector between teammate and the opponent. If you are able to send the ball to this line so that it's not intercepted, your teammate will be here faster. So, you then get a quadratic equation and the sign of its discriminant determines the answer

Everyting can be done in integers(rationals)

Anyone have solution code for E and H?

Nice tests in F (not a sarcasm), I wouldn't expect it was possible to fail $$$\varepsilon=10^{-8}$$$ within coordinates up to 75. If not for them I would have gotten AC within first hour :v

By the way it is possible to solve problem I in $$$O(n^3)$$$ even modulo anything instead of modulo 2. I actually think that is an easier solution than trick from editorial. Last cycle is either a loop (in that case we take answer from dp[n-1][k]) or it contains $$$n$$$ and $$$c$$$ for some number $$$c$$$ and it adds $$$2n-2c-1$$$ inversions, so we take answer from dp[n-2][k-2n+2c+1] then.

What's test 7 on C?