To improve the organization of his farm, Farmer John labels each of his N (1 <= N <= 5,000) cows with a distinct serial number in the range 1..20,000. Unfortunately, he is unaware that the cows interpret some serial numbers as better than others. In…

素数判断: 一.根据素数定义,该数除了1和它本身以外不再有其他的因数. 详见代码. int prime() { ; i*i<=n; i++) { ) //不是素数 ; //返回1 } ; //是素数返回0 } 二.打表,将所有的素数一一列出,存在一个数组里. 详见代码. void prime() { ; i<; i++) //从2开始一个一个找 { ) //这一个判断可以减少很多重复的,节省很多时间 { ; i*j<; j++) //只要乘以i就一定不是素数 { hash[i*j]=;…

看懂: Max Factor Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 3089    Accepted Submission(s): 985 Problem Description To improve the organization of his farm, Farmer John labels each of his N…

Max Factor Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 10245    Accepted Submission(s): 3304 Problem Description To improve the organization of his farm, Farmer John labels each of his N (1…

本文版权归ljh2000和博客园共有,欢迎转载,但须保留此声明,并给出原文链接,谢谢合作. 本文作者:ljh2000作者博客:http://www.cnblogs.com/ljh2000-jump/转载请注明出处,侵权必究,保留最终解释权!   Description To improve the organization of his farm, Farmer John labels each of his N (1 <= N <= 5,000) cows with a distinct s…

Problem Description To improve the organization of his farm, Farmer John labels each of his N (1 <= N <= 5,000) cows with a distinct serial number in the range 1..20,000. Unfortunately, he is unaware that the cows interpret some serial numbers as be…

本来是不打算贴这道水题的,自己却WA了三次.. 要考虑1的情况,1的质因子为1 思路:先打表 ,然后根据最大质因子更新结果 代码: #include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> using namespace std; #define MAX 20000 int p[MAX]; int main() { memset(p,,sizeof(p)); p[]=; ;…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=2710 思路:用类似“埃氏筛法”求素数的方法 只是不在把合数标记为1 而是标记为他是因子数. 最后比较大小即可. #include<cstdio> #include<cstring> ; int s[MAXN]; int main() { int n,m; memset (s,,sizeof(s)); s[]=; //经过该循环 ,s[j]代表 j是序列号 s[j]代表j的最大因子数,该方法…

这题就是先写个素数筛,存到prime里,之后遍历就好,取余,看是否等于0,如果等于0就更新,感觉自己说的不明白,引用下别人的话吧: 素数打表,找出20000之前的所有素数,存入prime数组,对于每个输入的数a,从prime数组最后一个数往前判断,如果a % prime[当前序号]== 0,那么将该素数就是输入数据a的最大素因子,找出所有输入数据的最大素因子,找出最大的那个对应的数据a即可,当a == 1的时候要特别处理. 然而我现在还是不懂,为什么输入是1 1的时候输出1,题目也没说啊,还有最…

题目 //下面这个是最先用的方法,因为学姐先讲完这个,所以懒得写代码,就将就着这个用,结果搞了老半天,还是错了,心累.. #include<stdio.h> #include<string.h> int prime[5010]; bool isprime[5010]; int solve(int n) { memset(prime,0,sizeof(prime)); int p=0; for(int i=0; i<=n; i++) isprime[i]=true; ispri…