Thread: Problem with my output

Or you could write:

Code:

          
if ( n % d == 0 )
      printf("%d\t", d);
d++;

Yep, that did it. Thanks. There is a good lesson in paying close attention to syntax.

So, if I wanted to take all the divisors and add them together, would I be best to create a function to store them into an array and then to return the sum of that array when it is complete or could I code something like that within main and not bother with a function? Either way, is there a way I can store them as they are discovered, so the program does not have to go through and get them later on?

Originally Posted by noops

Or you could write:

Code:

          
if ( n % d == 0 )
      printf("%d\t", d);
d++;

So the the if statement checks the truth of n%d being 0 and ignores anything else and then goes back to the loop for the next number? I haven't used '=='.

Originally Posted by Dogmasur

So the the if statement checks the truth of n%d being 0 and ignores anything else and then goes back to the loop for the next number? I haven't used '=='.

Yup. And for the sum you could use another variable to keep a running total. Whenever you find that n % d is 0 just add d to that running total variable. You will need brackets with the if statement if you add this.

edit: Also, '==' means 'equal to', and '=' means you are assigning a variable. be careful not to mix them up.

Code:

while ( d < n ) {
     if ( n % d  == 0 )
         printf("%d\t", d)
         d++;
}

Where should the enclosing braces go for adding my variable to keep track of the sum? I am using s as the variable, initialized it to 0, and my expression will read s = d + s.

You use the braces for 'if' just like you do for 'while'. So if(){stuff} will execute 'stuff' when the if is true.

Code:

if(condition)
{
     stuff;
     morestuff;
}

edit: also, you could look into using a 'for' loop for this.

I had my 'd++' inside the if braces and it was affecting my output. Now it's fixed. Thanks.

Here is the final code for my program, which seems to work fine.

Code:

/*write a program which accepts as input an integer (which must be 2 or greater)
 and prints out its proper divisors in ascending order, and the sum of its pro-
 per divisors.  The program should also report whether the input number is per-
 fect or not.*/
 
#include <stdio.h>
 
int main ( void )
{
     int n, d = 1, s = 0;
     
     printf("Enter a number greater than two:\t");
     scanf("%d", &n);
     getchar ();
     
     printf("The proper divisor(s) of %d is:\n", n);
     
     while ( d < n ){
           if ( n % d == 0 ){
                s = d + s;
                printf("%d\t", d);
                }     
                d++;
     }
     
     printf("\nThe sum of the divisors is %d.\n", s);
     
     if ( n == s )
         printf("%d is a perfect number.\n", n);
     else
         printf("%d is not a perfect number.\n", n);
     
     getchar();
     return 0;
                   
}

I see what you mean about the proper indentation. I didn't think I needed to initialize variable 'n' because it user-defined and is not used for any operations until the user has defined its value.

Good points. I understand what you're saying. Thanks.

Code:

printf("Enter a number greater than two:\t");
     scanf("%d", &n);
     getchar ();

Perhaps, you should write a proper function to clear off the input buffer, but not just using the getchar function to clear it. Since there might be more than one char until you reach EOF char, which needs to be cleared. Use the following function to clear the input buffer.

Code:

void Clear_Buffer( void )
{
     int ch;
     while( ( ch = getchar() ) != '\n' && ch != EOF );
}

And, try avoiding using scanf function.

ssharish