ThirdChallenge

package pl.kodolamacz;

public class Fraction {

    // Pola klasy Fraction
   public int numerator;
   public int denominator;



    //Metody klasy

    public String makeFraction(int numerator, int denominator){

        if (denominator == 1){
            return String.valueOf(numerator);
        }
        else if (denominator<0) {
            return (-numerator + "/" + -denominator);
        }
        else
            return (numerator + "/" + denominator);
        }

    public String getInteger(int numerator, int denominator){
        int a,b;
        if (numerator < 0) a = -numerator; else  a = numerator;
        if (denominator < 0) b = -denominator; else  b = denominator;
        if (denominator ==1) {
            return String.valueOf(numerator);
        }
        else if (a > b && a%b !=0 ) {
            return String.valueOf(numerator / denominator) + " " + makeFraction(a % b, b);

        }
         else {
             return makeFraction(numerator,denominator);

        }
    }

    //najwiekszy wspolny dzielnik - algorytm Euklidesa
    public int nwd(int a, int b){
        while( a != b){
            if (a<0) a = -a;
            if (b<0) b = -b;
            if (a > b) {
                    a -= b;
            }
            else
                    b -= a;
        }
        return a;
    }
    public String shortenFraction (int numerator,int denominator){

        if (denominator == 0) {
           return "Mianownik nie może być zerem!";
        }
        else if(numerator == denominator) {
            return "1";
        }
        else {
            return getInteger(numerator/nwd(numerator,denominator), denominator/nwd(numerator,denominator));
        }

    }
    public String sumOfFractions(int initNumerator, int initDenominator,int initNumerator2, int initDenominator2) {

        return shortenFraction(initNumerator*initDenominator2+initNumerator2*initDenominator,initDenominator*initDenominator2);
    }
    public String diffOfFractions(int initNumerator, int initDenominator,int initNumerator2, int initDenominator2) {

        return shortenFraction(initNumerator*initDenominator2-initNumerator2*initDenominator,initDenominator*initDenominator2);
    }

    public String prodOfFractions(int initNumerator, int initDenominator,int initNumerator2, int initDenominator2) {

        return shortenFraction(initNumerator*initNumerator2,initDenominator*initDenominator2);
    }

    public String qoutOfFractions(int initNumerator, int initDenominator,int initNumerator2, int initDenominator2) {

        return (prodOfFractions(initNumerator,initDenominator,initDenominator2,initNumerator2));
    }

}


package pl.kodolamacz;
import pl.kodolamacz.Fraction;
import java.util.Scanner;

public class ThirdChallenge {

    public static void main(String[] args){

        //Kalkulator
        String answer;
        do {
            System.out.println("Proszę podaj w oddzielnych linijkach liczbę, operację matematyczną (+,-,*,/,%), a następnie kolejną liczbę:");
            Scanner scanner = new Scanner(System.in);
            int numerator = scanner.nextInt();
            scanner.next();
            int denominator = scanner.nextInt();
            String operation = scanner.next();
            int numerator2 = scanner.nextInt();
            scanner.next();
            int denominator2 = scanner.nextInt();


            Fraction fraction1 = new Fraction();


            if (operation.equals("+")) {
                System.out.println("= " + (fraction1.sumOfFractions(numerator,denominator,numerator2,denominator2)));
            } else if (operation.equals("-")) {
                System.out.println("= " + (fraction1.diffOfFractions(numerator,denominator,numerator2,denominator2)));
            } else if (operation.equals("*")) {
                System.out.println("= " + (fraction1.prodOfFractions(numerator,denominator,numerator2,denominator2)));
            } else if (operation.equals("/") && numerator2 != 0) {
                System.out.println("= " + (fraction1.qoutOfFractions(numerator,denominator,numerator2,denominator2)));
            }else if (operation.equals("/") && numerator2 == 0){
                System.out.println("Dzielnik nie może być zerem!");
            } //else if (operation.equals("%")) {
               // System.out.println("= " + (x % y));
            //}
            else {
                System.out.println("Niepoprawna operacja!");
            }

            System.out.println("Czy chcesz wykonać kolejne działanie? (T/N) ");
            answer = scanner.next();

        } while (answer.equals("T"));

    }


}