/*  Write a C program that computes the value ex by using the formula 

ex= 1 + x/1! + x2/2! + x3/3! + ....

*/


#include<stdio.h>
#include<conio.h> 
void main()
{
int n,x,i;
float e=0.0;
long factorial(int); // Prototype declaration
float power(int,int); // Prototype declaration

clrscr();
printf("Enter the value of \'n\': ");
scanf("%d",&n);
printf("Enter the value of \'x\': ");
scanf("%d",&x);
for(i=0;i<=n;i++)
e += power(x,i)/(float)factorial(i);
printf("e^x = %-15.7f",e);
}

// Recursive factorial() function
long factorial(int n)
{
if(n<0)
return 0;
else if(n==0||n==1)
return((long)(1));
else
return((long)(n*factorial(n-1)));
}

// The power() function
float power(int a,int b)
{
int i,flag;
float p=1.0;
if(b<0)
b*=-1,flag=1;
else
flag=0;
for(i=1;i<=b;i++)
p *= a;
if(flag==0)
return p;
else
return (1/p);
}