C language programming＞The fifteenth week② Please write the function fun. Its function is to calculate: F=, F is returned as a function value. In C language, log(n) function can be called to find In(n). The reference description of log function is:

Example: Please write the function fun, its function is to calculate: F=, F is returned as the function value. In C language, you can call log(n) function to find In(n). The reference description of log function is: double log(double x)

例如，若n的值为10，则fun函数值为3.886440。
请勿改动主函数main与其它函数中的任何内容，仅在函数fun的花括号中填入所编写的若干语句。

代码如下：

#include<conio.h>
#include<math.h>
#include<stdio.h>
double fun(int n)
{
    
    
	int i;
	double f=0.0,log(double x);
	for(i=1;i<=n;i++)
		f=f+log(i);
	f=sqrt(f);
	return f;
}
main()
{
    
    
	int i;
	FILE*out;
	printf("%f\n",fun(10));
	out=fopen("outfile.dat","w");
	for(i=0;i<10;i++)
		fprintf(out,"%f\n",fun(i+15));
	fclose(out);
}

The output running window is as follows:

越努力越幸运！
加油，奥力给！！！