3981915_ac_204ms_312k.c

北大大牛代码 1240道题的原代码 超级权威

i,m,n;main(){while(scanf("%d",&m)+1,n=--m){if(m%2==0)n/=2;while(m%2==0)m/=2;for(i =3;m!=1;i+=2){if (m%i==0)n-=n/i;while(m%i==0)m/=i;}printf("%d\n",n);}}