题目链接:https://nanti.jisuanke.com/t/31452 A prime number (or a prime) is a natural number greater than $1$ that cannot be formed by multiplying two smaller natural numbers. Now lets define a number $N$ as the supreme number if and only if each number m…

题目链接:https://nanti.jisuanke.com/t/31453 After Incident, a feast is usually held in Hakurei Shrine. This time Reimu asked Kokoro to deliver a Nogaku show during the feast. To enjoy the show, every audience has to wear a Nogaku mask, and seat around as…

A prime number (or a prime) is a natural number greater than 11 that cannot be formed by multiplying two smaller natural numbers. Now lets define a number NN as the supreme number if and only if each number made up of an non-empty subsequence of all…

题目链接:https://nanti.jisuanke.com/t/31447 "Oh, There is a bipartite graph.""Make it Fantastic." X wants to check whether a bipartite graph is a fantastic graph. He has two fantastic numbers, and he wants to let all the degrees to between…

题目链接:https://nanti.jisuanke.com/t/30990 Alice, a student of grade 6, is thinking about an Olympian Math problem, but she feels so despair that she cries. And her classmate, Bob, has no idea about the problem. Thus he wants you to help him. The proble…

题目链接:https://nanti.jisuanke.com/t/31451 Given a rooted tree ( the root is node $1$ ) of $N$ nodes. Initially, each node has zero point. Then, you need to handle $Q$ operations. There're two types: 1 L X: Increase points by $X$ of all nodes whose dept…

interlinkage: https://nanti.jisuanke.com/t/38226 description: solution: 显然$\frac{\phi(j^2)}{\phi(j)}=j,\frac{\phi(k^3)}{\phi(k)}=k^2$ 原式可以化简为 $\sum_{i=1}^{n}\sum_{j=1}^n\sum_{k=1}^{n}jk^2\phi(gcd(i,j,k))$ 我们枚举$gcd(i,j,k)$,得 $\sum_{d=1}^{n}\phi(d)\sum…

题目链接:https://nanti.jisuanke.com/t/30996 During tea-drinking, princess, amongst other things, asked why has such a good-natured and cute Dragon imprisoned Lpl in the Castle? Dragon smiled enigmatically and answered that it is a big secret. After a pau…

题目链接:https://nanti.jisuanke.com/t/31460 Ryuji is not a good student, and he doesn't want to study. But there are n books he should learn, each book has its knowledge $a[i]$. Unfortunately, the longer he learns, the fewer he gets. That means, if he re…

题目链接:https://nanti.jisuanke.com/t/31459 样例输入 3 1 4 4 1 3 3 样例输出 10 题意: 二维平面上给出 $n$ 个点,每个点坐标 $\left( {x,y} \right)$ 代表一个从原点到 $\left( {x,y} \right)$ 的长方形, 其中标记红线为线段 $\left( {x,0} \right)\left( {x,y} \right)$ 和 $\left( {0,y} \right)\left( {x,y} \right)$…