这样?:
#include <iostream>
#include <algorithm>
double f(int n)
{
double Sum = 0.0;
for (int index = 1; index <= n; ++index)
{
Sum += log(index*1.0);
}
return sqrt(Sum);
}
int main()
{
std::cout << "f(10)的值为:" << f(10) << std::endl;//f(10)的值为:3.88644
return 0;
}