873. 欧拉函数

Posted 2021-05-23 幽殇默

https://www.acwing.com/problem/content/875/

#include<cstdio>
#include<iostream>
using namespace std;
int main(void)
{
	int n; cin>>n;
	while(n--)
	{
		int x; cin>>x;
		int res=x;
		for(int i=2;i<=x/i;i++)
		{
			if(x%i==0)
			{
				res=res/i*(i-1);
				while(x%i==0) x/=i;
			}
		}
		if(x!=1) res=res/x*(x-1);
		cout<<res<<endl; 
	}
}