Day7 - I - Semi-prime H-numbers POJ - 3292
This problem is based on an exercise of David Hilbert, who pedagogically suggested that one study the theory of 4n+1 numbers. Here, we do only a bit of that.
An H-number is a positive number which is one more than a multiple of four: 1, 5, 9, 13, 17, 21,... are the H-numbers. For this problem we pretend that these are the only numbers. The H-numbers are closed under multiplication.
As with regular integers, we partition the H-numbers into units, H-primes, and H-composites. 1 is the only unit. An H-number h is H-prime if it is not the unit, and is the product of two H-numbers in only one way: 1 × h. The rest of the numbers are H-composite.
For examples, the first few H-composites are: 5 × 5 = 25, 5 × 9 = 45, 5 × 13 = 65, 9 × 9 = 81, 5 × 17 = 85.
Your task is to count the number of H-semi-primes. An H-semi-prime is an H-number which is the product of exactly two H-primes. The two H-primes may be equal or different. In the example above, all five numbers are H-semi-primes. 125 = 5 × 5 × 5 is not an H-semi-prime, because it's the product of three H-primes.
Input
Each line of input contains an H-number ≤ 1,000,001. The last line of input contains 0 and this line should not be processed.
Output
For each inputted H-number h, print a line stating h and the number of H-semi-primes between 1 and h inclusive, separated by one space in the format shown in the sample.
Sample Input
21
85
789
0
Sample Output
21 0
85 5
789 62 思路:打表求出H-prime,再两两相乘,用树状数组优化求和问题即可
typedef long long LL;
typedef pair<LL, LL> PLL; const int maxm = 1e6+; bool prime[maxm];
int vis[maxm];
int jud[maxm], siz = , C[maxm]; void add(int x, int val) {
for(; x < maxm; x += lowbit(x))
C[x] += val;
} LL getsum(int x) {
LL ret = ;
for(; x; x -= lowbit(x))
ret += C[x];
return ret;
} void getHprime() {
for(int i = ; i < maxm; i += ) {
if(!prime[i]) {
for(int j = *i; j < maxm; j += i)
prime[j] = true;
jud[siz++] = i;
for(int k = ; k < siz; ++k) {
if(maxm / i >= jud[k]) {
if(!vis[jud[k] * i]++)
add(i*jud[k], );
} else
break;
} }
} } int main() {
getHprime();
int n;
while(scanf("%d", &n) && n) {
printf("%d %lld\n", n, getsum(n));
}
return ;
}
Day7 - I - Semi-prime H-numbers POJ - 3292的更多相关文章
- 【POJ 3292】 Semi-prime H-numbers
[POJ 3292] Semi-prime H-numbers 打个表 题意是1 5 9 13...这样的4的n次方+1定义为H-numbers H-numbers中仅仅由1*自己这一种方式组成 即没 ...
- POJ 3292 Semi-prime H-numbers (素数筛法变形)
题意:题目比较容易混淆,要搞清楚一点,这里面所有的定义都是在4×k+1(k>=0)这个封闭的集合而言的,不要跟我们常用的自然数集混淆. 题目要求我们计算 H-semi-primes, H-sem ...
- Day7 - J - Raising Modulo Numbers POJ - 1995
People are different. Some secretly read magazines full of interesting girls' pictures, others creat ...
- Sum of Consecutive Prime Numbers POJ - 2739 线性欧拉筛(线性欧拉筛证明)
题意:给一个数 可以写出多少种 连续素数的合 思路:直接线性筛 筛素数 暴力找就行 (素数到n/2就可以停下了,优化一个常数) 其中:线性筛的证明参考:https://blog.csdn.net ...
- Greedy:Sum of Consecutive Prime Numbers(POJ 2739)
素数之和 题目大意:一些整数可以表示成一个连续素数之和,给定一个整数要你找出可以表示这一个整数的连续整数序列的个数 方法:打表,然后用游标卡尺法即可 #include <iostream> ...
- A - Smith Numbers POJ
While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University,no ...
- POJ 3292 Semi-prime H-numbers
类似素数筛... Semi-prime H-numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 6873 Accept ...
- POJ 3292
Semi-prime H-numbers Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 7059 Accepted: 3 ...
- Prime Path(poj 3126)
Description The ministers of the cabinet were quite upset by the message from the Chief of Security ...
随机推荐
- css3内外阴影同时显示
内外阴影同时显示: box-shadow: 0px 0px 0.4rem rgba(255,255,255,0.5) inset,0px 0px 0.7rem rgba(185,119,143,0.9 ...
- VIM学习笔记一
键位图 转自:链接 永久显示行号: vi ~/.vimrc 加入 :set number 命令 简单说明 :w 保存编辑后的文件内容,但不退出vim编辑器.这个命令的作用是把内存缓冲区中的数据写到启动 ...
- Servlet读取xml文件的配置参数
web.xml中数据库连接配置: <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns: ...
- 如何用C++读取图片中的像素
来源:https://bbs.csdn.net/topics/391956973 3楼 #include <iostream> #include <fstream> #inc ...
- JNDI Java 命名与目录接口
jsp <% Context ctx = new InitialContext(); String jndiName = (String) ctx.lookup("java:comp/ ...
- Dynamic Programming(动态规划)
钢材分段问题 #include<iostream> #include<vector> using namespace std; class Solution { public: ...
- Codeforces 1260 ABC
DEF 题对于 wyh 来说过于毒瘤,十分不可做. A. Heating Description: 给定\(a,b\),将\(b\)分成至少\(a\)个正整数,使这些正整数的平方和最小. Soluti ...
- C-当把数组传递给函数
#include <stdio.h> /** * C语言中,数组的名称就是 一连串连续内存的起始地址, * 因此给数组传递给函数,传递的就是数组元素类型的指针 */ ]); void he ...
- 深入 Laravel 资料
深入 Laravel 核心 Learning_Laravel_Kernel laravel 源码详解
- 2_03_MSSQL课程_查询_分组和连接
“查” 的三种查询语句 where Group by having where 对表起作用 (原始硬盘上的表) 单纯的表 having 对结果起作用(筛选) 缓存,不在文件中 select --第 ...