摘要: 题意 给定 \(n\le 10^{18}\),规定数列 \(\{a_n\}\) 的通项公式:\(\displaystyle a_n=\sum^{n}_{i=1}i=\dfrac{n(n+1)}{2}\),以 \(\displaystyle P(a_i)=\dfrac{a_i}{\sum^{n}_{j 阅读全文
posted @ 2025-05-16 16:43 cold_jelly 阅读(18) 评论(0) 推荐(2)