题目链接 Problem Description Have you ever seen the wave? It's a wonderful view of nature. Little Q is attracted to such wonderful thing, he even likes everything that looks like wave. Formally, he defines a sequence a1,a2,...,an as ''wavel'' if and only…

题目链接 Problem Description zk has n numbers a1,a2,...,an. For each (i,j) satisfying 1≤i<j≤n, zk generates a new number (ai+aj). These new numbers could make up a new sequence b1,b2,...,bn(n−1)/2. LsF wants to make some trouble. While zk is sleeping, Ls…

题目链接 Problem Description As we know, Rikka is poor at math. Yuta is worrying about this situation, so he gives Rikka some math tasks to practice. There is one of them: Yuta has n positive A1−An and their sum is m. Then for each subset S of A, Yuta ca…

题目链接 Problem Description In the mathematical discipline of graph theory, a bipartite graph is a graph whose vertices can be divided into two disjoint sets U and V (that is, U and V are each independent sets) such that every edge connects a vertex in…

题目链接 Problem Description RXD is a good mathematician. One day he wants to calculate: ∑i=1nkμ2(i)×⌊nki−−−√⌋ output the answer module 109+7. 1≤n,k≤1018 μ(n)=1(n=1) μ(n)=(−1)k(n=p1p2-pk) μ(n)=0(otherwise) p1,p2,p3-pk are different prime numbers Input Th…

题目链接 Problem Description We define the distance of two strings A and B with same length n is disA,B=∑i=0n−1|Ai−Bn−1−i| The difference between the two characters is defined as the difference in ASCII. You should find the maximum length of two non-over…

题目链接 Problem Description Give an array A, the index starts from 1. Now we want to know Bi=maxi∤jAj , i≥2. Input The first line of the input gives the number of test cases T; T test cases follow. Each case begins with one line with one integer n : the…

题目链接 Problem Description Steph is extremely obsessed with "sequence problems" that are usually seen on magazines: Given the sequence 11, 23, 30, 35, what is the next number? Steph always finds them too easy for such a genius like himself until o…

题目链接 Problem Description In ACM/ICPC contest, the ''Dirt Ratio'' of a team is calculated in the following way. First let's ignore all the problems the team didn't pass, assume the team passed X problems during the contest, and submitted Y times for t…

题目链接 Problem Description At Valentine's eve, Shylock and Lucar were enjoying their time as any other couples. Suddenly, LSH, Boss of FFF Group caught both of them, and locked them into two separate cells of the jail randomly. But as the saying goes:…