relatives.txt

以前ACM在哈工程HRBEU做的一些简单题目

#include <stdio.h>
int main()
{
	long n,i;
	double sum;
	while(scanf("%ld",&n))
	{
		if(n==0)break;
		if(n==1)printf("0\n");
		else
		{
			sum=n;
			if(n%2==0)sum/=2;
			while(n%2==0)n/=2;
			for(i=3;n!=1;i+=2)
			{
				if(n%i==0)sum=sum-sum/i;
				while(n%i==0)n/=i;
			}
			printf("%.0lf\n",sum);
		}
	}
	return 0;
}