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Unable to understand while my while loop doesn't work (my first C exercise)

Hi.

Yes, a nb.
I have a problem with the following program I need to write as an essay.
assuming these are my variables:

startRange = 9
endRange = 20

I need to calculate which are the "powerfull" numbers, never mind what it means :)
the thing is that my while doesn't exit when it reaches the appropriate condition.

I am talking about the only while loop in this piece of code, so it won't be hard for you guys to find it :)

                  printf("Number : acceeding / powerfull\n");
                  for(currentNumber=startRange; currentNumber<=endRange; currentNumber++)
                  {
                        x=2;
                        while(currentNumber%x!=0 && x<currentNumber)
                        {
                              printf("%d",currentNumber);
                              printf("\n");
                              x++;
                        }
                  }

ozo

It looks like the while loop does exit when currentNumber%x ==0 or x>= currentNumber
if that is not what you wanted, do you consider to be appropriate condition?
It may be hard for you to see what x is in the loop since you never print it.

webiz

ASKER

well, it might look like it but it doesn't ;)
what I am getting is the following result:

9
11
11
11
11
11
11
11
11
11
13
13
13
13
13
13
13
13
13
13
13
15
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
and so on...

while I am supposed to get only
9
11
13
17
.....

ozo

well when currentNumber is 11, x will loop from 2 to 10, and then exit the loop when x=11 and && x<currentNumber fails
each time through the loop, you print currentNumber, so you print it 11-2 = 9 times

Why are you supposed to get 9 and not 15?

numansiddique

what do u mean by powerfull numbers. if we know what it means it will be better to understand the problem

ozo

if you want powers of primes, then you should have included 16

grg99

you're printing "currentnumber" in the loop, so you'll see that value repeated as many times as the loop goes around.

ASKER CERTIFIED SOLUTION

Kent Olsen

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