hdu 1286 找新朋友 (欧拉函数)

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<queue>
#include<stack>
#include<cmath>
using namespace std;
#define INF 0x3f3f3f3f
#define maxn 2100
int Euler(int x)
{
    int i,res = x;
    for(i = 2;i*i<=x;i++)
    {
        if(x%i==0)
            res = res/i*(i-1);
        while(x%i==0)
            x/=i;
    }
    if(x>1)
        res = res / x*(x-1);
    return res;
}//欧拉函数，寻找从1到n与n互质的数
int main()
{
    int t,n;
    scanf("%d",&t);
    while(t--)
    {
       scanf("%d",&n);
        printf("%d\n",Euler(n));
    }
    return 0;
}