# Greatest Common Factor

This is a discussion on Greatest Common Factor within the C Programming forums, part of the General Programming Boards category; I'm trying to reduce a fraction and I need to find the GCF. 20/8 would be reduced to 5/2. How ...

1. ## Greatest Common Factor

I'm trying to reduce a fraction and I need to find the GCF. 20/8 would be reduced to 5/2. How would I find the 4?

2. You should thank me: I coded this by hand for you in 3 minutes!

Code:
```int greatest_common_factor( int a, int b )
{
int i;
int result = 0;

for(i = 1; i <= a && i <= b; i++)
{
if( a % i == 0 && b % i == 0)
result = i;
}
return result;
}```

3. there is actually a much more elegant algorithm-look up Euclid's Algorithm

4. ## Greatest Common Factor

Hi idiots,

there is a recrsive function you may wish to use....
{in pascal code... haha, C-style syntax sucks ass!}

function GCF (a,b: integer): integer;
begin
if b<> 0
then
GCF:= GCF(b, a mod b)
else
GCF:= a;
end;

Computer science is the study of problem-solving, not of learning how to code in fifteen-thousand languages, you damn turds!

5. >Computer science is the study of problem-solving, not of
>learning how to code in fifteen-thousand languages, you damn
>turds!

This is the C-board, one of which goals is to learn C.

6. Here is how it is in C:

int GCF(int a,int b)
{
int gcf;

if(b!=0)
gcf=GCF(b, a%b);
else gcf=a;
return gcf;
}