Diophantus of Alexandria

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 2326    Accepted Submission(s): 887

Problem Description
Diophantus of Alexandria was an egypt mathematician living in Alexandria. He was one of the first mathematicians to study equations where variables were restricted to integral values. In honor of him, these equations are commonly called diophantine equations. One of the most famous diophantine equation is x^n + y^n = z^n. Fermat suggested that for n > 2, there are no solutions with positive integral values for x, y and z. A proof of this theorem (called Fermat's last theorem) was found only recently by Andrew Wiles.

Consider the following diophantine equation:

1 / x + 1 / y = 1 / n where x, y, n ∈ N+ (1)

Diophantus is interested in the following question: for a given n, how many distinct solutions (i. e., solutions satisfying x ≤ y) does equation (1) have? For example, for n = 4, there are exactly three distinct solutions:

1 / 5 + 1 / 20 = 1 / 4
1 / 6 + 1 / 12 = 1 / 4
1 / 8 + 1 / 8 = 1 / 4

Clearly, enumerating these solutions can become tedious for bigger values of n. Can you help Diophantus compute the number of distinct solutions for big values of n quickly?

Input
The first line contains the number of scenarios. Each scenario consists of one line containing a single number n (1 ≤ n ≤ 10^9). 
Output
The output for every scenario begins with a line containing "Scenario #i:", where i is the number of the scenario starting at 1. Next, print a single line with the number of distinct solutions of equation (1) for the given value of n. Terminate each scenario with a blank line. 
Sample Input
2
4
1260
Sample Output
Scenario #1: 3
Scenario #2: 113
令y = n + k (k >= 1), 则x = n^2/k + n , x为整数, 所以k为n^2的约数,因为x >= y, 所以k <= n, 所以
可以将问题简化为求n^2的不大于n的约数的个数,然后素数分解。
Accepted Code:
 /*************************************************************************
> File Name: 1299.cpp
> Author: Stomach_ache
> Mail: sudaweitong@gmail.com
> Created Time: 2014年07月10日 星期四 16时39分38秒
> Propose:
************************************************************************/ #include <cmath>
#include <string>
#include <cstdio>
#include <fstream>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std; int n;
int prime[];
bool vis[];
int cnt = ; void isPrime() {
cnt = ;
int k = (int)sqrt(1000000000.0) + ;
for (int i = ; i <= k; i++) vis[i] = true;
for (int i = ; i <= k; i++) {
if (vis[i]) {
prime[cnt++] = i;
for (int j = i*i; j <= k; j += i) vis[j] = false;
}
}
} int main(void) {
isPrime();
int c = ;
int t;
scanf("%d", &t);
while (t--) {
scanf("%d", &n);
int ans = ;
for (int i = ; i < cnt && prime[i] <= n; i++) {
int tmp = ;
while (n % prime[i] == ) {
tmp++;
n /= prime[i];
}
ans *= + * tmp;
}
if (n > ) ans *= ;
printf("Scenario #%d:\n", c++);
printf("%d\n\n", (ans + ) / );
} return ;
}
 
 

Hdu 1299的更多相关文章

  1. hdu 1299 Diophantus of Alexandria(数学题)

    题目链接:hdu 1299 Diophantus of Alexandria 题意: 给你一个n,让你找1/x+1/y=1/n的方案数. 题解: 对于这种数学题,一般都变变形,找找规律,通过打表我们可 ...

  2. HDU 1299 基础数论 分解

    给一个数n问有多少种x,y的组合使$\frac{1}{x}+\frac{1}{y}=\frac{1}{n},x<=y$满足,设y = k + n,代入得到$x = \frac{n^2}{k} + ...

  3. hdu 1299 Diophantus of Alexandria (数论)

    Diophantus of Alexandria Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java ...

  4. hdu 1299 Diophantus of Alexandria

    1/x + 1/y = 1/n 1<=n<=10^9给你 n 求符合要求的x,y有多少对 x<=y// 首先 x>n 那么设 x=n+m 那么 1/y= 1/n - 1/(n+ ...

  5. 数学--数论--HDU 1299 +POJ 2917 Diophantus of Alexandria (因子个数函数+公式推导)

    Diophantus of Alexandria was an egypt mathematician living in Alexandria. He was one of the first ma ...

  6. 求n的因子个数与其因子数之和

    方法一:朴素算法:O(n). #include<bits/stdc++.h> using namespace std; int get_num(int n){ ; ;i<=n;++i ...

  7. HDOJ Problem - 1299

    题意:等式 1 / x + 1 / y = 1 / n (x, y, n ∈ N+ (1) 且 x <= y) ,给出 n,求有多少满足该式子的解.(1 <= n <= 1e9) 题 ...

  8. HDU——PKU题目分类

    HDU 模拟题, 枚举1002 1004 1013 1015 1017 1020 1022 1029 1031 1033 1034 1035 1036 1037 1039 1042 1047 1048 ...

  9. hdu 1573 X问题 (非互质的中国剩余定理)

    X问题 Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submiss ...

随机推荐

  1. Jetty启动配置解析

    目录 1. jetty概述 2. spring-jetty启动配置 1. jetty概述 维基百科:Jetty是一个纯粹的基于Java的网页服务器和Java Servlet容器. Jetty Serv ...

  2. google移动版针对智能手机、非智能手机的蜘蛛的User-agent

    非智能手机蜘蛛的User-agent有以下两个 SAMSUNG-SGH-E250/1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/6.2. ...

  3. 最小费用最大流——EK+SPFA

    终于把最小费用最大流学会了啊-- 各种奇奇怪怪的解释我已经看多了,但在某些大佬的指点下,我终于会了. 原来是个好水的东西. 最小费用最大流是什么? 不可能不知道网络流吧?如果不知道,自行百度去-- 费 ...

  4. webpack配置根据浏览器自动添加css前缀的loader

    1.安装 postcss-loader autoprefixer npm install postcss-loader autoprefixer --save-dev 2.配置webpack.conf ...

  5. SQLSERVER 数据库管理员的专用连接DAC

    DAC:Dedicated Admin Connection 当SQL Server因系统资源不足,或其它异常导致无法建立数据库连接时, 可以使用系统预留的DAC连接到数据库,进行一些问题诊断和故障排 ...

  6. PAT甲级——A1020 Tree Traversals

    Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and i ...

  7. 构建支持中文字体的moviepy镜像

    首先是系统的环境问题. linux 安装 moviepy需要很多依赖,安装起来费神费力.配置起来也非常麻烦,最简单的办法是直接使用他人构建好的镜像文件. 再就是字体显示问题. 镜像中的imagmagi ...

  8. idea创建管理项目

    创建分支时以master为准,这时master上的代码已合并完毕,idea右下角可以看到本地和远程的分支,在本地合并时,先切换到master上,选中要合并到master的分支,选择merge into ...

  9. pytorch 加载训练好的模型做inference

    前提: 模型参数和结构是分别保存的 1. 构建模型(# load model graph) model = MODEL() 2.加载模型参数(# load model state_dict) mode ...

  10. Luogu P2764 最小路径覆盖问题(二分图匹配)

    P2764 最小路径覆盖问题 题面 题目描述 «问题描述: 给定有向图 \(G=(V,E)\) .设 \(P\) 是 \(G\) 的一个简单路(顶点不相交)的集合.如果 \(V\) 中每个顶点恰好在 ...