Solution -「营业」「ABC 209F」Deforestation
Description Link. 有 $n$ 棵树,每棵的高度为 $a(i)$,看到一棵树对答案的贡献为 $a(i-1)+a(i)+a(i+1)$(...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.