TextLab05st.java

// TextLab05st.java
// The Rational Class Program II
// This is the student, starting version of the Text Lab 05 assignment.
// There are 5 return methods in the Rational class that have temporary return statements
// which allow the program to compile.  Students will need to change these statements.


/* Tyler Beaver

I changed things a little bit.
Namely I changed the add/multiply/sub/divide
methods to static methods returning
new objects as that makes much more sense
in a higher level language than the former
assembly style operations.

Also I added the built-in ascii fraction symbols.
That's pretty cool I should get bonus points for
that. srsly tho.

*/

import java.util.Scanner;


public class TextLab05st
{
    static int num1, den1;   // numerator and denominator of the 1st rational number
    static int num2, den2;   // numerator and denominator of the 2nd rational number

    public static void main (String args[])
    {
        enterData();

        Rational r1 = new Rational(num1,den1);
        Rational r2 = new Rational(num2,den2);
        Rational r3 = null; // I chaned some stuff -
                            // It makes more sense for operators to be static.
                            // why do we not use the built in features, anyways?

        r3 = Rational.multiply(r1,r2);
        System.out.println("\n\n" + r1.getOriginal() + " * " + r2.getOriginal() + "  =  " + r3.getRational());
        r3 = Rational.divide(r1,r2);
        System.out.println("\n" + r1.getOriginal() + " / " + r2.getOriginal() + "  =  " + r3.getRational());

        r3 = Rational.add(r1,r2);
        System.out.println("\n" + r1.getOriginal() + " + " + r2.getOriginal() + "  =  " + r3.getRational());
        r3 = Rational.subtract(r1,r2);
        System.out.println("\n" + r1.getOriginal() + " - " + r2.getOriginal() + "  =  " + r3.getRational());
        System.out.println();
    }

    public static void enterData()
    {
        Scanner input = new Scanner(System.in);
        System.out.print("\nEnter the 1st numerator ----> ");
        num1 = input.nextInt();
        System.out.print("\nEnter the 1st denominator --> ");
        den1 = input.nextInt();
        System.out.print("\nEnter the 2nd numerator ----> ");
        num2 = input.nextInt();
        System.out.print("\nEnter the 2nd denominator --> ");
        den2 = input.nextInt();
    }
}

class Rational
{
  protected int _num, _den;
  protected final int firstNum, firstDen;

    public Rational(int numerator, int denom)
    {
        firstNum = numerator;
        firstDen = denom;
        reduce();
    }

    public static Rational multiply(Rational r1, Rational r2)
    {
        return new Rational(r1._num * r2._num, r1._den * r2._den);
    }

    public static Rational divide(Rational r1, Rational r2)
    {
        return new Rational(r1._num * r2._den, r1._den * r2._num);
    }

    public static Rational add(Rational r1, Rational r2)
    {
        int n1=r1._num, n2=r2._num, d1 = r1._den, d2=r2._den;
        int n = n1 * d2 + n2 * d1, d = d1 * d2;
        return new Rational(n,d);
    }

    public static Rational subtract(Rational r1, Rational r2)
    {
        int n1=r1._num, n2=r2._num, d1 = r1._den, d2=r2._den;
        int n = n1 * d2 - n2 * d1, d = d1 * d2;
        return new Rational(n,d);
    }

    public int getNum() { return _num; }

    public int getDen() { return _den; }

    public double getDecimal() { return ((double)_num/(double)_den); }

  public static String format(int _num,int _den){
    String base = "";
    if(_num<0||_den<0){
      if(!(_num<0&&_den<0)){
        base+="-";
      }
      if(_num<0)
        _num*=-1;
      if(_den<0)
        _den*=-1;
    }
    if(_num==1){
      switch(_den){
        case 1:
          return base+"⅟";
        case 2:
          return base+"½";
        case 3:
          return base+"⅓";
        case 4:
          return base+"¼";
        case 5:
          return base+"⅕";
        case 6:
          return base+"⅙";
        case 8:
          return base+"⅛";
      }
    } else if(_num==2){
      switch(_den){
        case 3:
          return base+"⅔";
        case 5:
          return base+"⅖";
      }
    } else if(_num==3){
      switch(_den){
        case 4:
          return base+"¾";
        case 5:
          return base+"⅗";
        case 8:
          return base+"⅜";
      }
    } else if(_num==4&&_den==5) {
      return "⅘";
    } else if(_den==8){
      if(_num==5){
          return base+"⅝";
      } else if(_num==7){
          return base+"⅞";
      }
    }
    return base+ _num + "/" + _den;
  }

    public String getRational() {
    return format(_num,_den);
  }

    public String getOriginal() { return format(firstNum,firstDen); }

    protected void reduce()
    {
        int cden = getGCF(firstNum,firstDen);
        _num = firstNum / cden;
        _den = firstDen / cden;
    }

    public void displayData()
    {
        System.out.println();
        System.out.println(getOriginal() + " equals " + getDecimal());
        System.out.println();
        System.out.println("and reduces to " + getRational());
        System.out.println();

    }

    private int getGCF(int n1,int n2)
    {
        int rem = 0, gcf = 0;
        do
        {
            rem = n1 % n2;
            if (rem == 0)
                gcf = n2;
            else
            {
                n1 = n2;
                n2 = rem;
            }
        }
        while (rem != 0);
        return gcf;
    }
}