ARC091B
考えたこと
条件を満たす数を素朴に探すと10^10でダメ
各bごとに計算
kより小さいなら0
大きいならNをbで割る→q, r
ret = q * (b - k)
r > k なら ret += r - k
公式解説OK
1つズレてるけどテストケースですぐ直せるでしょう
"Engineer's way of creating knowledge" the English version of my book is now available on [Engineer's way of creating knowledge]
(C)NISHIO Hirokazu / Converted from [Scrapbox] at [Edit]