B has a simple solution, I(and probably the problemsetters too) don't get why people tend to overcomplicate things for problems like A and B which can be solved with naive solutions most of the times.

For example, even though I obviously know how to solve B in O(n log n), it wasn't needed in this case, and O(5000^2) works fine enough and it's simple to write.

Also, in the end, no matter how strong the initial tests are, they are still pretests so fails can come at any problem

Sum of times in which you get accepted + 10 minutes * amount of wrong submissions

If you hack someone's solution, you (may) climb 1 place. Your ranking will increase(or decrease, in case you get hacked).

Penalty is meant to separate contestants with the same amount of problems solved.

Compiler optimizes simple stuff and makes them O(1). Given that CF is very fast, such solutions will pass system tests too

Compiler optimizations

After some precalculations, one can do bitmask DP to find the maximum answer 48133701

My recurrence relation was DP[mask][first line][last line]

After some precalculations, one can do bitmask DP to find the maximum answer

My recurrence relation was DP[mask][first line][last line]

You can construct the solution for x from solution of (x-4)

Base cases: n = 0 => ans = 0, n = 1 => ans = 1, n = 2 => ans = 1, n = 3 => ans = 0