n！的长度(斯特林公式)

链接:http://www.51nod.com/Challenge/Problem.html#!#problemId=1130

特林公式以及本题参考代码:https://blog.csdn.net/qq_41003528/article/details/82840908

#include
#include
#include
#include
#include
#define pi 3.1415926535
using namespace std;

int main(){
	int t;
	long long res;
	double ans,n;
	cin>>t;
	while(t--){
		cin>>n;
		ans = 1;
		ans += log10(2.0*pi*n)/2+n*log10(n/exp(1));
		res = (long long ) ans;
		cout<