hdu1787-GCD Again
http://acm.hdu.edu.cn/showproblem.php?pid=1787
非数组形式,用于大数据
#include<iostream> #include<cstdio> #include<algorithm> #include<cstring> using namespace std ; #define INT __int64 int enlerfun( int n ) { int tempnum = 1 ; int i ; for( i = 2 ; i * i <= n ; ++i ) { if( n % i == 0 ) { n /= i ; tempnum *= ( i - 1 ) ; while( n % i == 0 ) { n /= i ; tempnum *= i ; } } } if( n > 1 ) tempnum *= ( n - 1 ) ; return tempnum ; } int main() { int n ; int count ; while( ~scanf( "%d" , &n ) && n ) { printf( "%d\n" , n - 1 - enlerfun( n ) ) ; } return 0 ; }