在一段区间[l,r]内,找出因数最多的数的个数以及其因数个数. 用唯一分解定理将一个数分解成质因数的乘积,例如 2^p1*3^p2*5^p3*7^p4*....  从这些质因数中任选出一些数相乘,都可以组成原数的因数,总方案数为(p1+1)*(p2+1)*(p3+1)*...   注:+1是因为可以不选,全部不选的话得到数字1,也是原数的因数. r<=1000000000,对其开根号得到31622,也就是说不会存在两个以上大于31622的质因数.素数筛算出1~3w+的质数.接下来用唯一分解定理算…

Content 给定 \(n\) 个区间 \([l,r]\),求出每个区间内约数个数最大的数. 数据范围:\(1\leqslant l<r\leqslant 10^{10}\),\(r-l\leqslant 10^4\). Solution 你可能需要在做这题目前了解一下约数个数定理.何谓约数个数定理? 设一个数 \(x\) 的个数可以分解为若干个质因数相乘的积,即: \[x=\prod\limits_{i=1}^k p_i^{a_i} \] 那么 \(x\) 的约数个数 \(f(x)\) 有一…

E. Number With The Given Amount Of Divisors time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Given the number n, find the smallest positive integer which has exactly n divisors. It is guara…

Description A number whose only prime factors are 2,3,5 or 7 is called a humble number. The sequence 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 24, 25, 27, ... shows the first 20 humble numbers. Now given a humble number, please write…

计算小于n的数中,约数个数最多的数,若有多个最输出最小的一个数. http://hihocoder.com/problemset/problem/1187 对于100有 60 = 2 * 2 * 3 * 5,共 (2 + 1) * (1 + 1) * (1 + 1) = 12个约数. 对于 n <= 10 ^ 16,int最大值为10位,所以这里要用long long.很显然:约数要尽量小,然后小的约数的指数一定大于大的约数的指数. 所以对于 10^16,有质因子:2,3,5,7,11,13,1…

Xenia and Divisors time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Xenia the mathematician has a sequence consisting of n (n is divisible by 3) positive integers, each of them is at most 7…

传送门 时间限制:10000ms 单点时限:1000ms 内存限制:256MB 描述 Given an integer n, for all integers not larger than n, find the integer with the most divisors. If there is more than one integer with the same number of divisors, print the minimum one. 输入 One line with an…

The number of divisors(约数) about Humble Numbers Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2044    Accepted Submission(s): 1006 Problem DescriptionA number whose only prime factors are 2,3,…

Problem Description mmm is learning division, she's so proud of herself that she can figure out the sum of all the divisors of numbers no larger than 100 within one day!But her teacher said "What if I ask you to give not only the sum but the square-s…

B. Petya and Divisors Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/111/problem/B Description Little Petya loves looking for numbers' divisors. One day Petya came across the following problem: You are given n queries in t…