摘要: 1656D - K-good n is k-good if and only if $ n \geq 1 + 2 + \ldots + k = \frac{k(k+1)}{2}.$ \(n \equiv 1 + 2 + \ldots + k \equiv \frac{k(k+1)}{2} \pmod 阅读全文
posted @ 2022-03-26 18:49 seekerHeron 阅读(54) 评论(0) 推荐(0)