原题链接题解关键要素：两次后缀和预处理\(d<\sqrt{n}\)的情况，当\(d\)大于\(\sqrt{n}\)时，直接暴力，总时间复杂度为\(O(n\sqrt{n})\)代码比讲述要清晰，请直接看代码code#include<bits/stdc++.h>#definelllonglongusingnamespacestd;lla[100005]={0};llsufs1[100335][

B-ArithmeticProgressionSubsequenceProblemStatementYouaregivenasequence$A$oflength$N$consistingofintegersbetween$1$and$\textbf{10}$,inclusive.Apairofintegers$(l,r)$satisfying$1\leql\leqr\leqN$iscalledagoodpairif

F.SumofProgressionYouaregivenanarray$a$of$n$numbers.Therearealso$q$queriesoftheform$s,d,k$.Foreachquery$q$,findthesumofelements$a_s+a_{s+d}\cdot2+\dots+a_{s+d\cdot(k-1)}\cdotk$.Inotherwords,foreach

题目链接：CF一道经典的类型题，把这种类型的题拿出来单独说一下。注意到问题中涉及到需要维护\(a_{x+k\timesstep}\)这样的信息，这样的信息很难用树型结构维护，比较容易用块级结构维护，我们注意到其实是每次这种步长\(+step\)的信息很难维护，我们考虑一类特殊的分块：如果\(step\)

ArithmeticProgression题目大意存在一个打乱了顺序的等差数列\(a\)，你可以询问不超过\(60\)次，每次可以以以下两种方式之一进行询问：查询\(a\)中是否有严格大于\(x\)的数。查询\(a_i\)的值。你需要求出这个等差数列的首项和公差。思路分析比较有意思的题。看

/***1502.CanMakeArithmeticProgressionFromSequence*https://leetcode.com/problems/can-make-arithmetic-progression-from-sequence/description/*Asequenceofnumbersiscalledanarithmeticprogressionifthedifferencebetweenanytwoconsecut

Genalovessequencesofnumbers.Recently,hehasdiscoveredanewtypeofsequenceswhichhecalledanalmostarithmeticalprogression.Asequenceisanalmostarithmeticalprogression,ifitselementscanberepresentedas:a1 = p,wherepissomeintege

11129-AnantiarithmeticpermutationTimelimit:3.000secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=113&page=show_problem&problem=2070Apermutationof n+1 isabijectivefunctionoftheinitial n+1

E-GeometricProgressionhttps://atcoder.jp/contests/abc293/tasks/abc293_e 思路根据矩阵递推式找出转移矩阵的幂形式。利用矩阵快速幂计算。     

ProblemStatementConstructaset$S$ofintegerssatisfyingalloftheconditionsbelow.Itcanbeprovedthatatleastonesuchset$S$existsundertheConst

Forexamplewehaveasearchinput:constinput$=fromEvent(document.getElementById("#input"),"input");input$.pipe(debounceTime(200),pluck("ta

题目大意: 给出一个数组A,然后一个1到x的所有数,让你把这些数插入到A里面,使得插入后的序列ai和ai+1绝对值差的和最小,求出这个最小值即可思路: 要素

GCDProblem-D-Codeforces题意有2个等差数列A，B，它们公有的项组成新的等差数列C；现在给出B的（首项，公差，项数）=（b，q，y），C的（首项，公差，项数）=（c，r，z）求满足条件的A的数量，如

CF1194A-RemoveaProgressionA.RemoveaProgressionYouhavealistofnumbersfrom\(1\)to\(n\)writtenfromlefttorightontheblackboard.Youperform