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  1. #include <bits/stdc++.h>
  2. #define II ({int a; scanf("%d", &a); a;})
  3. #define LL  ({ll  a; scanf("%lld", &a); a;})
  4. #define pi acos(0.0)
  5. using namespace std;
  6. typedef  long long ll;
  7.  
  8. ll  phi ( ll  n ) {
  9. 	ll  i,res = n ;
  10. 	for (  i = 2 ; i * i <= n ; ++ i )
  11. 		if ( n % i == 0 ) {
  12. 			while ( n % i == 0 )
  13. 				n /= i ;
  14. 			res -= res / i ;
  15. 		}
  16. 	if ( n > 1 ) res -= res / n ;
  17. 	return res ;
  18. }
  19.  
  20. int main(){
  21.     ll n ;
  22.     while(scanf("%lld",&n) && n ){
  23.         if( n == 1 ) puts("0");
  24.         else printf("%lld\n",phi(n));
  25.     }
  26. }
Success #stdin #stdout 0s 4460KB
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https://ideone.com/pUMS71
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
public

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