Sgu 102. Coprimes

gcd,暴力枚举

#include<stdio.h>int gcd(int a,int b){if(a<b)return gcd(b,a);if(b==0)return a;return gcd(b,a%b);}int main(){int n;while(scanf("%d",&n)!=EOF&&n){int i,res=0;for(i=1;i<=n;i++)if(gcd(n,i)==1)res++;printf("%d\n",res);}return 0;}