Alexandra and Prime Numbers Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1658 Accepted Submission(s): 565 Problem Description Alexandra has a little brother. He is new to programming. One…
题意: 给一个正整数N,找最小的M,使得N可以整除M,且N/M是质数. 数据范围: There are multiple test cases (no more than 1,000). Each case contains only one positive integer N.N≤1,000,000,000.Number of cases with N>1,000,000 is no more than 100. 思路: N=M*prime 故必有M或prime小于等于sqrt(N)…
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5108 题目意思:给出一个数正整数 N,N <= 1e9,现在需要找出一个最少的正整数 M,使得 N/M 是素数.如果找不到就输出0. 一开始有想过将所有 <= 1e9 的素数求出来的,不过绝对超时就放弃了:然后就开始从题目中挖掘简便的处理方法.受到求素数的方法启发,枚举的因子 i 如果在 i * i <= N 之内都没有找到符合条件的素数,那么那些 > N 的因子就更不可能了.于是时间…
Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 20050 Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…
题目链接: 传送门 Sum of Consecutive Prime Numbers Time Limit: 1000MS Memory Limit: 65536K Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representations does a given positive intege…
Sieve of Eratosthenes (素数筛选算法) Given a number n, print all primes smaller than or equal to n. It is also given that n is a small number. For example, if n is 10, the output should be “2, 3, 5, 7″. If n is 20, the output should be “2, 3, 5, 7, 11, 13,…
Problem Description Give you a lot of positive integers, just to find out how many prime numbers there are. Input There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won't exceed 32-…
