Basic arithemetic on rational numbers

[RIsagara]

Hi
Modify this where possible

[yellowSnow]

Hi
Modify this where possible

And what exactly do you want to modify? Ask a specific question.

[Beg.CProgrammer]

"interger" is spelled "integer"
"valve" is spelled "value"

[RIsagara]

And what exactly do you want to modify? Ask a specific question.

you realize that it cannot give 0/4=0,
I also limited the user from entering 0,
modify the Gcd method to reduce the fraction recursively,

[RIsagara]

/*A PROGRAM PERFORMING BASIC ARITHMETIC ON RATIONAL NUMBERS*/

 /*BY ISAGARA K ROBERT*/
 /*26th october 2009*/
 /*THIS WAS MY ASSIGNMENT(COMPUTER SCIENCE YEAR II) TO MR PAUL BAGYENDA ON BASIC  ARITHMETIC OPERATION ON RATIONAL NUMBERS*/

#include <stdio.h>
#include <stdlib.h>



typedef struct rational_t {
     int numer;
     int denom;
} rational_t;
/*modify this for me*/
static int gcd(int a, int b)
{ int c;
  while(a>0)
    {  
           if(a<b)
             { c=a;
                a=b;
                b=c;
                        }
            else
             a=a%b;
   }
  return b;                  
}

/* r_init: creates rational number representing numer/denom and returns it*/
rational_t  r_init(int numer, int denom)
{    
    rational_t fraction; 
    int GcD=gcd(numer,denom);
    fraction.numer= numer/GcD;
    fraction.denom= denom/GcD;
    return fraction;
}

/* r_add: Returns a rational_t representing x+y */
rational_t  r_add(rational_t  x, rational_t  y)
{
    rational_t result;
    result.numer=(x.numer*y.denom+ x.denom* y.numer);
    result.denom=(x.denom*y.denom);
    return result;
}

/* r_sub: Returns a rational_t representing x-y */
rational_t  r_sub(rational_t  x, rational_t  y)
{
    rational_t result;
   result.numer=(x.numer*y.denom - x.denom* y.numer);
   result.denom=(x.denom*y.denom);
   return result;
}

/* r_mul: Returns a rational_t representing x*y */
rational_t  r_mul(rational_t  x, rational_t  y)
{   rational_t result;
    result.numer=(x.numer*y.numer);
    result.denom=(x.denom*y.denom);
    return result;
 }

/* r_div: Returns a rational_t representing x/y */
rational_t  r_div(rational_t  x, rational_t  y)
{
    rational_t result;
    result.numer=(x.numer*y.denom);
    result.denom=(x.denom*y.numer);
     return result;
}

/* r_toreal: Returns a double representing x */
double r_toreal(rational_t  x)
{
}

/* r_print: prints rational as x/y (using printf */
void r_print(rational_t  x)
{
     int p=gcd(x.numer,x.denom);
     printf("%d/%d",x.numer/p,x.denom/p);
}

int main(void)
{
   printf("Rational arithmetic test program\n");
      do {
      int u,v, oper;
      rational_t x, y, z;
      here:
      printf("x - numerator: ");
      scanf("%d", &u);
        if(u==0){
                printf("Enter interger greater than Zero\n");
                      goto here;}     
      There1:
      printf("x - denominator: ");
      scanf("%d", &v);
       if(v==0){
                      printf("Zero is  undefined for  a fraction ,Enter valve above Zero\n");
                      goto There1;
      }
        x = r_init(u,v);
        here2:
      printf("y - numerator: ");
      scanf("%d", &u);
        if(u==0){
                printf("Enter interger greater than Zero\n");
                      goto here2;}
       Thereback:
      printf("y - denominator: ");
      scanf("%d", &v);
      if(v==0){
                       printf("Zero is undefined for  a fraction ,Enter valve above Zero\n");
                       goto Thereback;
      }
      y = r_init(u,v);

      printf("x is: ");
      r_print(x);
      printf("\n");

      printf("y is: ");
      r_print(y);
      printf("\n");

      printf("Operation (1=add,2=Sub,3=Mul,4=Div,0=End): ");
      scanf("%d", &oper);

      switch (oper) {
      case 1:
           z = r_add(x,y);
           break;
      case 2:
           z = r_sub(x,y);
           break;
      case 3:
           z = r_mul(x,y);
           break;
      case 4:
           z = r_div(x,y);
           break;
      case 0:
           return 0;
      default:
           printf("Unknown operation!\n");
           break;
      }

      printf("z is: ");
      r_print(z);
      printf("\n");  
     } while(1);

     return 0;
}

[RIsagara]

Gentle thanks for the modification but I did not really mean sp