摘要: $1.$ 核酸检测(defend) $$f[i] = f[j] + (i - j - 1) * (i - j) /2 + a[i]$$ $$f[j] + j * (j + 1) / 2 = i * j + f[i] - a[i] - i * (i - 1) / 2$$ $$Y(f[j] + j * 阅读全文
posted @ 2022-07-02 07:49 Altwilio 阅读(32) 评论(0) 推荐(0) 编辑