編寫函數fun，功能是計算下列級數和，和值由函數值返回，s=1+x+x^2/2!+......+x^n/n!,當n=10,x=0.3,函數值為1.349859

#include<conio.h>
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
double fun(double x, int n)
{
  int i;
  double s=1.0,k=1.0;
  for(i=1;i<=n;i++)
  {
		  k=k*i;
	  
		  s=s+pow(x,i)/k;
  }
		  return s;
}
void main()
{ 
  FILE *wf;
  system("CLS");
  printf("%f ",fun(0.3,10));
/******************************/
  wf=fopen("out.dat","w");
  fprintf(wf,"%f",fun(0.3,10));
  fclose(wf);
/*****************************/
}