题目描述 定义 \(d(n)\) 为 \(n\) 的正因数的个数,比如 \(d(2) = 2, d(6) = 4\). 令 $ S_1(n) = \sum_{i=1}^n d(i) $ 给定 \(n\),求 \(S_1(n)\). 输入格式 第一行包含一个正整数 \(T\) (\(T \leq 10^5\)),表示数据组数. 接下来的 \(T\) 行,每行包含一个正整数 \(n\) (\(n < 2^{63}\)). 输出格式 对于每个 \(n\),输出一行一个整数,表示 \(S_1(n)\)…

Counting Divisors Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 3170    Accepted Submission(s): 1184 Problem Description In mathematics, the function d(n) denotes the number of divisors of…

Counting Divisors Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others) Problem Description In mathematics, the function d(n) denotes the number of divisors of positive integer n. For example, d(12)=6 because 1,2,3,4,…

题目 vjudge URL:Counting Divisors (square) Let σ0(n)\sigma_0(n)σ0​(n) be the number of positive divisors of nnn. For example, σ0(1)=1\sigma_0(1) = 1σ0​(1)=1, σ0(2)=2\sigma_0(2) = 2σ0​(2)=2 and σ0(6)=4\sigma_0(6) = 4σ0​(6)=4. Let S2(n)=∑i=1nσ0(i2).S_2(n…

Counting Divisors Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 1604    Accepted Submission(s): 592 Problem Description In mathematics, the function d(n) denotes the number of divisors of p…

DIVCNT2 - Counting Divisors (square) DIVCNT3 - Counting Divisors (cube) 杜教筛 [学习笔记]杜教筛 (其实不算是杜教筛,类似杜教筛的复杂度分析而已) 你要大力推式子: 把约数个数代换了 把2^质因子个数 代换了 构造出卷积,然后大于n^(2/3)还要搞出约数个数的式子和无完全平方数的个数的容斥... .... 然后恭喜你,spoj上过不去... bzoj能过: #include<bits/stdc++.h> #define…

地址:http://acm.split.hdu.edu.cn/showproblem.php?pid=6069 题目: Counting Divisors Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 1235    Accepted Submission(s): 433 Problem Description In mathem…

/** 题目:hdu6069 Counting Divisors 链接:http://acm.hdu.edu.cn/showproblem.php?pid=6069 题意:求[l,r]内所有数的k次方的约数个数之和. 思路: 用(1+e1)*(1+e2)*...*(1+en)的公式计算约数个数. 素数筛出[l,r]内的素因子,然后直接计算结果.(一开始我用vector存起来,之后再处理,结果超时, 时间卡的很紧的时候,vector也会很占用时间.) */ #include<iostream>…

DIVCNT2 - Counting Divisors (square) #sub-linear #dirichlet-generating-function Let \sigma_0(n)σ​0​​(n) be the number of positive divisors of nn. For example, \sigma_0(1) = 1σ​0​​(1)=1, \sigma_0(2) = 2σ​0​​(2)=2 and \sigma_0(6) = 4σ​0​​(6)=4. LetS_2(…

Counting Divisors Time Limit: 10000/5000 MS (Java/Others)    Memory Limit: 524288/524288 K (Java/Others)Total Submission(s): 2599    Accepted Submission(s): 959 Problem Description In mathematics, the function d(n) denotes the number of divisors of p…