/* Write a C program that estimates the value of the mathematical constant e by using the formula: 

e = 1 + 1/1! + 1/2! + 1/3! + …...

*/


#include<stdio.h> 
main() 
{ 
int n,i,f=1,j; 
float e = 1.0; 
clrscr(); 
start: 
printf("Enter n value: "); 
scanf("%d",&n); 
if(n<0) 
{ 
printf("Please enter non-negetive value\n"); 
goto start; 
} 
for(i = 1;i<=n;i++) 
{ 
for(j = 1;j<=i;j++) 
{ 
f = f*j; 
} 
e=e+((float)1/f); 
f=1; 
} 
printf("Result is: %f\n",(float)e); 
getche(); 
}