Thread: Calculating GCD

Hello,

I have made a programm which calculated the GCD of two numbers.

Code:

#include        <stdio.h>


int
main ( int argc, char *argv[] )
{
        int getal1, getal2, tmp, uitkomst, rest ;

        tmp = 0 ;
        printf ("Enter the two numbers where the GCD must be calculated  \n")
        printf ("Please first the little number and then the greatest number. ");
        scanf ("%d %d", &getal1, &getal2) ;
        uitkomst = getal2 / getal1 ;
        rest  = getal2 - uitkomst * getal1;
        while (rest > 1)
                {
                        tmp = getal1 ;
                        getal2 = getal1 ;
                        getal1 = rest ;
                        uitkomst = getal2/getal1 ;
                        rest = getal2 - uitkomst * getal1;
                }
        if (rest == 0)
                printf("The GCD is %d",getal1 );
        else
                printf("There is no GCD");
        return 0 ;

For me it works.
But I wonder if you experts have anything to say about the programm.

Roelof

Also, why do you bother with tmp?

oke,

Let's say we use the numbers 210 and 57
So uitkomst will be 210 / 57 = 3
rest will be 210 - 3*57 = 39
tmp = 57
getal2 = 57
getal1= 39
uitkomst = 57 / 39 = 1
rest = 57 - 39 = 18
and so on.

tabstop . yore right. I don't need tmp.

Roelof

Originally Posted by roelof

oke,
tabstop . yore right. I don't need tmp.

Roelof

I just hate it when he does that!

Commontator :

I don't get it what you mean with your message.

Roelof

Oke,

and any remarks on my program where I can learn things.

Roelof

Originally Posted by roelof

Oke,

and any remarks on my program where I can learn things.

Roelof

Looks good to me. Probably pretty close to what I would write (but I'm no math head...). It looks like you did some pruning and minimizing which is always a good thing.

I think you're doing just fine my friend.

So, what's next?

next 2 assigments are :

1) Write a program that's ask a user to enter a fraction, then reduces the fraction to the lowest term.

That's a easy one. I only have to change some things in the GCD programm

2) Change a earlier programm so the user can calculate things till the user enters 0

That are assigments 3 and 4 of the 12 of the loop chapter

Roelof

Cool... sounds like fun.

Hello,

Yep, a lot of fun.
I can send you a pdf copy of the book im following.

Next chapter is about the data types with a lot of execting exercices.

Roelof

Originally Posted by roelof

Hello,

Yep, a lot of fun.
I can send you a pdf copy of the book im following.

Next chapter is about the data types with a lot of execting exercices.

Roelof

If you could post a link to it... I'd like to add it to my collection.

Commontator:

Here 1 link I found the book : C Programming: A Modern Approach, 2nd Edition (Repost)

Roelof

Thanks...