#include <stdio.h>

/** Struct describing a Fraction */
typedef struct Fraction
{
    int num; // numerator
    int den; // denominator
} Fraction;

/** Returns the gcd of the fraction */
int frc_gcd (Fraction f)
{
    int reminder;
    while ( f.num != 0 )
    {
        reminder = f.num; 
        f.num = f.den % f.num;  
        f.den = reminder;
    }

    return f.den;
}

/** Simplify the given fraction 
 *  Both numerator and denominator gets divided by the gcd of them 
 **/
void frc_simplify(Fraction* f) {
    int gcdValue = frc_gcd(*f);
    f->num = f->num / gcdValue;
    f->den = f->den / gcdValue;
}

/** Prints the fraction formatted
 *  If denominator is 1 it's omitted
 **/
void frc_print(Fraction f){
    f.den != 1 ?
        printf("%d/%d", f.num, f.den) : 
        printf("%d", f.num);
}

int main (int argc, const char * argv[]) {

    Fraction f = {6,3};
    frc_simplify(&f);

    printf("In lowest terms:");
    frc_print(f);
}