zoj 1526 Big Number

#include <iostream>#include <math.h>using namespace std;const double e= 2.718281828459 ;const double pi= 3.1415926535898 ;int main(){     long long n,tt;     cin>>tt;     while(tt>0)     {         tt--;         cin>>n;         long long ans = (long long)((double)log10(sqrt(2* pi * n)) + n * log10(n / e))+1;         cout<<ans<<endl;     }     return 0;}