NK_1214: Relatives

 1 /*
 2  *今天看了一下欧拉函数，找了个水题练了一下
 3  *
 4  */
 5 
 6 
 7 #include <iostream>
 8 using namespace std;
 9 int eular(int n)
10 {
11         int ret=1;
12         for(int i=2;i*i<=n;i++)
13         {
14                 if(n%i==0)
15                 {
16                         ret*=(i-1);
17                         n/=i;
18                         while(n%i==0)
19                         {
20                                 n/=i;
21                                 ret*=i;
22                         }
23                 }
24         //     if(n<i)
25         //             break;
26         }
27         if(n>1)
28                 ret*=(n-1);
29         return ret;
30 
31 }
32 int main()
33 {
34         int t;
35         while(cin>>t,t!=0)
36         {
37                 cout<<eular(t)<<endl;
38         }
39 }