Thread: Need help with calculating a sum :/

As I'm informed about the rules, I won't ask you to write all of the code.. The problem i am trying to overcome is that:
Write a program that approximates e by computing the value of :
e=1+1/1!+1/2!+1/3!....+1/n! (user will enter the value "n")

So, my code is as it's written below;
But results are not satisfying when i execute the program.. I ask you to find my mistake and inform me about it. Thanx.

Code:

#include <stdio.h>
int main ()
{
    int k, n, x;
    float total, denom;
    scanf("%d", &n);
    k=1;
    denom=1;
    total=1;
    while(n>=k){
        x=n;
        for(;x>0; x--){
            denom=denom*x;
        }


        total+=1.0f/denom;
        n--;
    }
    printf("Result:%.4f\n", total);
    return 0;
}

You need to set denom to 1 inside the loop.

OMG ! I spent my 2 days just for this I'm so grateful sir. Thank you very much "qny" !

Originally Posted by Salem

Try using a debugger, or at a push, some debug print statements.

Code:

    while(n>=k){
        x=n;
        for(;x>0; x--){
            denom=denom*x;
        }
        printf("Fact(%d)=%f\n",n,denom);

        total+=1.0f/denom;
        n--;
    }

Are these factorials?

Yes Salem. My first loop (while) for the sum of (1/denom)s, and the second one (for) for factorials.. And thanx for your reply.

Yes Grumpy, maybe it is as you said sir. But consider that i am a beginner in c programming approach as you can understand from my coding. And i've learned until loops, that's why I insist on using nested loops. Thanks for your reply.