need a little help with ths problem

I need to compute the sum of 1 + 1 * 2 + 1 * 2 * 3.... n (n being the number). so if n was 5 it would be 1 + 1 * 2 + 1 * 2 * 3 + 1 * 2 * 3 * 4 + 1 * 2 * 3 * 4 * 5 (exiting at 5). so far I got this, but i need correction on my for loop because I think it is wrong.


#include <stdio.h>
main ()
{
long n, i, sum=0;
printf ("enter number to be summed");
scanf ("%d", &n);
for (i=1; i <=n,i++)


I'm not too sure what to put for the sum I was thinking maybe sum+= i * i but that doesn't look right. maybe i should set sum to 1? any help would be appreciated.

Code:

---

sum = 1;
for (i=2; i <=n,i++)
  sum += sum * i

---

Okay, you have a program which needs to sum up the factorials. Here's my suggestion...

Start up by just writing a program that will print them... here's some example output:

Code:

---

facsum.exe

Enter a number to be summed: 5
1
2
6
24
120

---

Seriously, just write that program. Once you have that done, go back to your code, and at some point in it you will have a line that looks like this...

Code:

---

printf ("%d\n", num); // print the factorial

---

Switch that line with something like

Code:

---

sum += num

---

And viola, your program.

does my code work?

nutshell's program was similar to the one i made, and it gave wrong values. question c gave good advice, but i need to do this problem with a for loop. I just can't think of a good way to go around it.

Code:

---

sum = 1;

for(i = 2; i <= n; i++)
{
        sum2 = 1;

        for(j = 2; j <= i; j++)
        {
                sum2 *= j;
        }
        sum += sum2;
}

---

nice monster, guess i should re-read the nested for loop crap again. thanks .