Relatives

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 16186		Accepted: 8208

Description

Given n, a positive integer, how many positive integers less than n are relatively prime to n? Two integers a and b are relatively prime if there are no integers x > 1, y > 0, z > 0 such that a = xy and b = xz.

Input

There are several test cases. For each test case, standard input contains a line with n <= 1,000,000,000. A line containing 0 follows the last case.

Output

For each test case there should be single line of output answering the question posed above.

Sample Input

Sample Output

Source

欧拉函数模板题

AC代码

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                #define ll long long#define ms(a) memset(a,0,sizeof(a))#define pi acos(-1.0)#define INF 0x3f3f3f3fconst double E=exp(1);using namespace std;const int maxn=1e6+10;int a[maxn];int b[maxn];//欧拉函数公式：//φ(N)=N*(1-1/P1)*(1-1/P2)*...*(1-1/Pn).int main(int argc, char const *argv[]){ int n; while(cin>>n&&n) { ms(b); ll ans=n; int vis=n; for(int i=2;i*i<=vis;i++) { if(vis%i==0) { ans=ans/i*(i-1); while(vis%i==0) { vis/=i; } } } if(vis>1) ans=ans/vis*(vis-1); cout<
                
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                  1)res =res/a*(a-1);//res -= res/a;// return res;// } // ******************第二种打表求解****************// #define Max 1000001// int euler[Max];// void Euler()// {// euler[1]=1;// for(int i=2;i