HDU 5430 Reflect

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=5430

Problem Description

We send a light from one point on a mirror material circle,it reflectsN times and return the original point firstly.Your task is calcuate the number of schemes.

 

Input

First line contains a single integer T(T≤10) which denotes the number of test cases.

For each test case, there is an positive integer N(N≤106).

 

Output

For each case, output the answer.

 

Sample Input

14

 

Sample Output

4

若入射角为a，则圆心角为2a，由于刚好回到原点，则2a*（N+1）必须为2kπ，其中k可以为任意整数，不难发现，只要a和N+1是互质数即可满足要求，判断是否是互质数我们可以求他们的公约数，如果求不出公约数的话，那就说明它们互质了。代码如下：

#include<iostream>using namespace std;int fun(int i,int n){int temp;while(i!=0&&i!=1){temp=n%i;n=i;i=temp;}return i;}int main(){int T;cin>>T;while(T--){int n;cin>>n;int cnt=0;for(int i=1;i<=n;i++){if(fun(i,n+1)){//cout<<"yes";cnt++;}//else cout<<"no";}cout<<cnt<<endl;}return 0;}