题意:给一个排列p,m次查询l,r,\(\sum_{i=l}^r\sum_{j=i+1}^r\sum_{k=j+1}^r[gcd(p_i,p_j)==p_k]p_k\) 题解:离线,枚举右端点,对于每个数在i位置的数\(p_i\),考虑前面所有是\(p_i\)的倍数的位置,假设是\(t_1,t_2,...,t_x\)从后往前枚举,那么对于\(t_j\)来说,所有在\(t_j\)到\(i\)之间的位置,假设有k个位置和\(t_j\)gcd为\(a_i\),那么对于右端点在i,左端点在\(t_j\)…

// 判断相同区间(lazy) 多校8 HDU 5828 Rikka with Sequence // 题意:三种操作,1增加值,2开根,3求和 // 思路:这题与HDU 4027 和HDU 5634 差不多 // 注意开根号的话,遇到极差等于1的,开根号以后有可能还是差1.如 // 2 3 2 3... // 8 9 8 9... // 2 3 2 3... // 8 9 8 9... // 剩下就是遇到区间相等的话,就直接开根号不往下传 #include <bits/stdc++.h> u…

2017 多校3 hdu 6061 RXD and functions(FFT) 题意: 给一个函数\(f(x)=\sum_{i=0}^{n}c_i \cdot x^{i}\) 求\(g(x) = f(x - \sum a_i)\)后每一项\(x^{i}\)的系数mod998244353 \(n <= 10^{5},m <= 10^{5}\) \(0 <= c_i < 998244353\) \(0 <= a_i < 998244353\) 思路: 令\(d = -\s…

2017 多校2 hdu 6053 TrickGCD 题目: You are given an array \(A\) , and Zhu wants to know there are how many different array \(B\) satisfy the following conditions? \(1≤B_i≤A_i\) For each pair(\(l , r) (1≤l≤r≤n) , gcd(bl,bl+1...br)≥2\) Input The first line…

个人感觉题解的复杂度很玄,参不透,有没有大佬讲解一下- - /* HDU 6102 - GCDispower [ 数论,树状数组] | 2017 Multi-University Training Contest 6 题意: 给定排列 a[N], M 组 L,R 求解 ∑ [ L <= i < j < k <= R ] [ GCD(a[i], a[j]) == a[k] ] * a[k] 限制:N, M <= 1e5 分析: 数论角度一般考虑枚举 k,由于是区间询问,且贡献有…

题目传送: Hybrid Crystals Problem Description > Kyber crystals, also called the living crystal or simply the kyber, and known as kaiburr crystals in ancient times, were rare, Force-attuned crystals that grew in nature and were found on scattered planets…

题目传送:Killer Names Problem Description > Galen Marek, codenamed Starkiller, was a male Human apprentice of the Sith Lord Darth Vader. A powerful Force-user who lived during the era of the Galactic Empire, Marek originated from the Wookiee home planet…

题目传送:http://acm.hdu.edu.cn/showproblem.php?pid=6045 Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 687    Accepted Submission(s): 389 Problem Description Derek and Alfia are good friends.Derek …

Problem Description HazelFan is given two positive integers a,b, and he wants to calculate amodb. But now he forgets the value of b and only remember the value of a, please tell him the number of different possible results.   Input The first line con…

Problem Description This is Kolakosiki sequence: 1,2,2,1,1,2,1,2,2,1,2,2,1,1,2,1,1,2,2,1……. This sequence consists of 1 and 2, and its first term equals 1. Besides, if you see adjacent and equal terms as one group, you will get 1,22,11,2,1,22,1,22,11…