log10(n!)=log10(2*pi*n)*0.5+n*log10(n/e)

注意long long

1 #include
     
       2 #include
      
        3 #include
       
         4 #include
        
          5 #include
         
           6 #define ll long long 7 #define pi 3.1415926535 8 #define E 2.718281828459 9 using namespace std;10 const int mod=1e9+7;11 int n,x;12 int main(){13     cin>>n;14     for(int i=1;i<=n;i++){15         cin>>x;16         double s=log10(2*pi*x)*0.5+x*(log10(x/E));17         cout<<(long long)(s)+1<