依次进行 $1$ 次 $+$，$3$ 次 $-$，$9$ 次 $+$ ……，就能在不超过 $18m$ 次询问内走到 $0$（最大值仅在 $m=2$ 时取到），然后再做 $+$ 和 $-$ 各一次，如果仍在 $0$ 则为 Ugly，否则根据 $+$ 和 $-$ 次数的多少可以判断是 Good 还是 Bad。
QOJ.ac
QOJ
As we are currently experiencing an overwhelming number of web requests for fetching user submissions, we have temporarily disabled the full submissions list. You must now be logged in to view submissions.
Discussion #358 for Problem #12310. The Good, the Bad and the Ugly
Type: Editorial
Status: Open
Posted by: jiangly
Posted at: 2025-12-14 07:17:12
Last updated: 2025-12-14 07:17:17
题解
Comments
No comments yet.