Looking for a solution to task C of the recent atcoder grand contest since the editorial given is only in Japanese. I tried converting it to english but it's a very bad conversion.

I cannot understand how you can verify in O(N) if its possible to satisfy the given condition by using at max X distinct characters. (the check(X) function used in Binary search)

Auto comment: topic has been updated by thehumbleguy (previous revision, new revision, compare).You may watch Petr's screencast with commentary for hints:

AtCoder Grand Contest 029 screencast with commentary

Sorry for the delay, we'll finish it within this week.

Inside the binary search, basically, we decide

S_{1},S_{2}, ... greedily.S_{1}should be the lexicographically minimum string of lengthA_{1}. Then,S_{2}should be the lexicographically minimum string of lengthA_{2}that is greater thanS_{1}. But we need to do this efficiently.how do you guys think? its so frustating for me to think the solution of problem c.I tried for 2 hour and nothing come up with solution.

with practice you will able to come up

yes i am practicing,but sometime my mind dont able to think even problem A, it take approx 15-20 min to solve A(lol) , i can solve A B but no able to solve that fucking C.hope practicing will help me

its so frustating for me to think the solution of problem cask god why he gave you a less intelligent brain. lol. do you really have to beat yourself up over this? Everyone has his/her own strengths. Go and find yours.

I wondered what is your real account

how about say that this is my real account?