/*******************************************************************************
 * Třída Fraction 
 *
 * @author    Tomáš Pitner
 * @version   1.00, 10.8.2005
 */
public class Fraction {

    private int numerator;
    private int denominator;

    /***************************************************************************
     * 
     */
    public Fraction(int n, int d) {
        if(d == 0) {
            throw new IllegalArgumentException(
                "Cannot create fraction with denominator 0");
        }
        numerator = n;
        denominator = d;
    }

    public int getNumerator() {
        return numerator;
    }
    
    public int getDenominator() {
        return denominator;
    }
    
    public static Fraction add(Fraction f1, Fraction f2) {
        Fraction result = new Fraction(
            f1.getNumerator() * f2.getDenominator() 
                + f1.getDenominator() * f2.getNumerator(), 
            f1.getDenominator()*f2.getDenominator());
        return result;
    }
    
    public static Fraction multiply(Fraction f1, Fraction f2) {
        Fraction result = new Fraction(
            f1.getNumerator()*f2.getNumerator(), 
            f1.getDenominator()*f2.getDenominator());
        return result;
    }
    
    public static Fraction subtract(Fraction f1, Fraction f2) {
        Fraction result = new Fraction(
            f1.getNumerator() * f2.getDenominator() 
                - f1.getDenominator() * f2.getNumerator(), 
            f1.getDenominator()*f2.getDenominator());
        return result;
    }
    
    public static Fraction divide(Fraction f1, Fraction f2) {
        try {
            Fraction result = new Fraction(
                f1.getNumerator()*f2.getDenominator(), 
                f1.getDenominator()*f2.getNumerator());
                return result;
        } catch(IllegalArgumentException iae) {
            throw new IllegalArgumentException("Cannot divide fraction by 0");
        }    
    }
    
    public String toString() {
        return ""+getNumerator()+"/"+getDenominator();
    }
    
}