struct again

[duffy]

how do i extend the struct number type to add the fraction type, and how do i extend the display funtion so that it also handles fractional numbers, displaying them in the format numerator / denominator.
(thanx stoned coder by the way)

****************struct fraction************* 
struct fraction 
{ 
double numerator; 
double demoninator; 
} 

double Agg( struct fraction* frac) 

{ 
return frac->numerator + frac->denominator; 
} 


****************Program to extend***************** 

enum tag { is_int, is_double }; 

union value { 
int i; 
double d; 
}; 

struct number { 
enum tag t; 
union value v; 
}; 

void display (struct number n) { 
switch (n.t) { 
case is_int: 
printf("%d", n.v.i); break; 
case is_double: 
printf("%g", n.v.d); break; 
}; 
} 

struct number plus (struct number n1, struct number n2) { 
struct number result; 
if (n1.t == is_int && n2.t == is_int) { 
result.t = is_int; 
result.v.i = n1.v.i + n2.v.i; 
} else { 
result.t = is_double; 
result.v.d = 0.0; 
result.v.d += n1.t == is_double ? n1.v.d : (double)n1.v.i; 
result.v.d += n2.t == is_double ? n2.v.d : (double)n2.v.i; 
} 
return result; 
} 

int main () { 
struct number x; 
struct number pi; 
x.t = is_int; x.v.i = 42; 
pi.t = is_double; pi.v.d = 3.14159; 
display(plus(x, pi)); 
}

[Magos]

The formula for adding two fractions (?) is this: (a / b) + (c / d) = ((a * d) + (b * c)) / (b * d)

[duffy]

No i dont think thats right, does anyone else have any ieas?

[Magos]

Pure mathematically that formula is correct. But if that wasn't what you asked for, then please be more specific.

BTW: You should really try to make the code better structured. It is rather hard to read...

[duffy]

i dont want to actually add two fractions together, i want to add the fraction function to the rest of the code.... they are two separate pieces of code, and i want them together, and then i want to extend the function called display so that it handles fractional numbers, displaying them in the format numerator / denominator.

[Magos]

Here's something for you to look at:

typedef struct
{
   double Numerator;
   double Demoninator;
}FRACTION;


FRACTION CreateFraction(double Numerator, double Denominator)
{
   FRACTION Number;
   Number.Numerator = Numerator;
   Number.Denominator = Denominator;
   return Number;
}


void PrintFraction(FRACTION Number)
{
   printf("%g/%g", Number.Numerator, Number.Denominator);
}


int main()
{
   FRACTION MyFraction = CreateFraction(34, 7);
   PrintFraction(MyFraction);
   getch(); //If you have conio.h
   return 0;
}