simplify fractions

[AmLegacy]

I'm having a hard time figuring out how to simplify the fractions. Can anyone look at this code and see if you can see something I don't.

[CODE=c]//This is the fraction adding function
void add_fractions (int a, int b, int c, int d, int *ansn, int *ansd)
{
//int e, x, y, rem, gcd;
a = a*d; //numerator 1 * denominator 2
c = c*b; //numerator 2 * denominator 1
b = b*d; // denominator 1 * denominator 2
d = b; //denominator 2 = denominator 1
//e = c + a;
if ( d == 0 && b == 0)
{
printf ("Answer is undefined \n");//denominator = to 0 case
}

*ansn = a + c;
*ansd = d;
}

//This is the fraction subtraction function

void subtract_fracti ons (int a, int b, int c, int d, int *ansn, int *ansd)
{
a = a*d; //numerator 1 * denominator 2
c = c*b; //numerator 2 * denominator 1
b = b*d; // denominator 1 * denominator 2
d = b; //denominator 2 = denominator 1

if ( d == 0 && b == 0)
{
printf ("Answer is undefined \n");//denomiator = to 0 case
}

*ansn = a - c;
*ansd = d;
}


//This is the fraction multiplication function

void multiply_fracti ons (int a, int b, int c, int d, int *ansn, int *ansd)
{
a = a*c; //numerator 1 * numerator 2
c = a; // numerator 2 = numerator 1
b = b*d; //denominator 1 * denominator 2
d = b; //denominator 2 = denominator 1

if ( d == 0 && b == 0)
{
printf ("Answer is undefined \n");
}

*ansn = a;
*ansd = b;

}

//This is the fraction division function
void divide_fraction s (int a, int b, int c, int d, int *ansn, int *ansd)
{
a = a*d; //numerator 1 * denominator 2
d = a; //denominator 2 = to numerator 1
b = b*c; //denominator 1 * numerator 2
c = b; // numerator 2 = denominator 1

if ( d == 0 && b == 0)
{
printf ("Answer is undefined \n");
}

*ansn = a;
*ansd = b;

}




int main ()
{
int a_num, b_denom, c_num, d_denom;
int ans1, ans2;
int operation;
int simplify;
int x,y;
int rem, gcd;



printf ("Please enter the first numerator> \n");
scanf ("%d", &a_num);

printf ("Please enter the first denominator> \n ");
scanf ("%d", &b_denom);

printf ("Please enter the second numerator> \n ");
scanf ("%d", &c_num);

printf ("Please enter the second denominator> \n ");
scanf ("%d", &d_denom);


printf ("Please enter 1 for addition, 2 for subtraction, 3 for multiplication, or 4 for division> \n");
scanf ("%d", &operation);



if (operation == 1)

{

add_fractions (a_num, b_denom, c_num, d_denom, &ans1, &ans2);

printf ("Your answer is %d/%d \n\n", ans1, ans2);

}

else
if (operation == 2)

{

subtract_fracti ons (a_num, b_denom, c_num, d_denom, &ans1, &ans2);

printf ("Your answer is %d/%d \n", ans1, ans2);

}

else
if (operation == 3)

{

multiply_fracti ons (a_num, b_denom, c_num, d_denom, &ans1, &ans2);

printf ("Your answer is %d/%d \n", ans1, ans2);

}

else
if (operation == 4)

{

divide_fraction s (a_num, b_denom, c_num, d_denom, &ans1, &ans2);

printf ("Your answer is %d/%d \n", ans1, ans2);

}


else

{

printf ("No Real Solutions \n");

}

printf("Do you want to reduce the fraction? \n Press 1 for yes and 2 for no> \n");
scanf ("%d", &simplify);

if (simplify == 1)

{if (y==0)
gcd = x;
else
{
do
{
rem = x%y;
x = y;
y = rem;


}
while (y!=0);
gcd = x;

printf ("%d", &x);
}

}

if (simplify == 2)
{
printf("Your answer is %d/%d", ans1, ans2);
}
}[/CODE]

[Ganon11]

At the very end, I see you using printf() to print an integer (%d), but you give it &x, which will point the address of x. Aside from this, I don't see any place where you use the greatest common denominator to reduce the fraction. You might clean up that code by writing a gcd() function - it would certainly look nicer.