ABC felt a bit too difficult, even though I enjoyed them. E is alright — maybe a bit more enjoyable if we solve for first player, but then it'd be too easy. Gap E-F is hard, but maybe it's my skill issue :). Overall felt kind of balanced.
What I can't understand is the intended solution for D: whatever you do, you need to keep track of the two sorted sets, and be able to recover an element by index and vice versa. This is either a lot of pain to implement, or a no-brainer pbds. For div1 that's alright either way (I did a pbds), but I feel sorry for less experienced participants: if you don't know pbds, you'll likely have a really hard time debugging the implementation yourself, even though the greedy idea is a good one for this position.
ABC felt a bit too difficult, even though I enjoyed them. E is alright — maybe a bit more enjoyable if we solve for first player, but then it'd be too easy. Gap E-F is hard, but maybe it's my skill issue :). Overall felt kind of balanced.
What I can't understand is the intended solution for D: whatever you do, you need to keep track of the two sorted sets, and be able to recover an element by index and vice versa. This is either a lot of pain to implement, or a no-brainer pbds. For div1 that's alright either way (I did a pbds), but I feel sorry for less experienced participants: if you don't know pbds, you'll likely have a really hard time debugging the implementation yourself, even though the greedy idea is a good one for this position.