抄起我的混凝土数学，复习了会上升下降积分，看了看斯特林数和伯努利数。结果误把伯努利数的递推式看成了$O(n)$的，改了半天一到3次方以上就翻

HDU6319 Ascending Rating Before the start of contest, there are n ICPC contestants waiting in a long queue. They are labeled by 1 to n from left to right. It can be easily found that the i-th contestant’s QodeForces rating is ai. Little Q, the coach of Quailty Normal University, is bored to just watch them waiting in the queue. He starts to compare the rating of the contestants. He

Alice 想要得到一个长度为 n 的序列，序列中的数都是不超过 m 的正整数，而且这 n 个数的和是 p 的倍数。 Alice 还希望，这 n 个数中，至少有一个数是质数。 Alice 想知道

Wu got hungry after an intense training session, and came to a nearby store to buy his favourite instant noodles. After Wu paid for his purchase, the cashier gave him an interesting task. You are given a bipartite graph with positive integers in all vertices of the right half. For a subset 𝑆 of vertices of the left half we define 𝑁(𝑆) as the set of all

Roma is playing a new expansion for his favorite game World of Darkraft. He made a new character and is going for his first grind. Roma has a choice to buy exactly one of 𝑛 different weapons and exactly one of 𝑚 different armor sets. Weapon 𝑖 has attack modifier 𝑎𝑖 and is worth 𝑐𝑎𝑖 coins, and armor set 𝑗 has defense modifier 𝑏𝑗 and is

没注意到数据范围是100。 You are given a string 𝑠 consisting of lowercase Latin letters. Let the length of 𝑠 be |𝑠|. You may perform several operations on this string. In one operation, you can choose some index 𝑖 and remove the 𝑖-th character of 𝑠 (𝑠𝑖) if at least one of