#include "rational.h"
#include <stdio.h>

long gcd( long m, long n ) {
	long tmp;

	while ( m != 0 ) {
		tmp = m;
		m = n % m;
		n = tmp;
	}

	return n;
}

bool rational_init( rational_t *p_r, long num, long den ) {
	if ( den == 0 ) {
		return false;
	} else {
		// Eliminate any common denominator
		long div = gcd( num, den );
		num /= div;
		den /= div;

		// Ensure the numerator is negative
		if ( den >= 0 ) {
			p_r->numerator   =  num;
			p_r->denominator =  den;
		} else {
			p_r->numerator   = -num;
			p_r->denominator = -den;
		}
	}
} 

bool rational_multiply( rational_t *p_r, rational_t q ) {
	long div_1 = gcd( p_r->numerator,   q.denominator );
	long div_2 = gcd( p_r->denominator, q.numerator );

	p_r->numerator /= div_1;
	p_r->numerator *= (q.numerator/div_2);

	p_r->denominator /= div_2;
	p_r->denominator *= (q.denominator/div_1);
}

// If the rational number is of the form num/1, print 'num';
// otherwise print 'num/den'
int rational_printf( rational_t *p_r ) {
	if ( p_r->denominator == 1 ) {
		return printf( "%d",    p_r->numerator );
	} else {
		return printf( "%d/%d", p_r->numerator,  p_r->denominator );
	}
}