import java.util.Random;
public class fraction {
    private int numerator, denominator;//numerator分子，denominator分母

    public fraction(int numer, int  denom) {
        if ( denom == 0)
            denom = 1;

        if ( denom< 0) {
            denom =  denom * -1;
            numer = numer * -1;
        }

        numerator = numer;
        denominator =  denom;

        reduce();
    }

    public int getNumerator() {
        return numerator;
    }

    public int getDenominator() {
        return denominator;
    }

    public fraction reciprocal() {
        return new fraction(denominator, numerator);
    }

    public fraction add(fraction op2)//加法，例如2/3+1/2=(2*2+1*3)/(2*3)
    {
        int commonDenominator = denominator * op2.getDenominator();//和的分母等于分母之积
        int numerator1 = numerator * op2.getDenominator();//第一个数的分子乘以第二个数的分母
        int numerator2 = op2.getNumerator() * denominator;//第二个数的分子乘以第一个数的分母
        int sum = numerator1 + numerator2;//sum和的分子
        System.out.print("(" + this.toString() + ")" + " + " + "(" + op2.toString() + ")" + "=");
        return new fraction(sum, commonDenominator);//sum分子，commonDenominator分母
    }

    public fraction subtract(fraction op2)//减法，例如2/3-1/2=(2*2-1*3)/(2*3)
    {
        int commonDenominator = denominator * op2.getDenominator();//差的分母
        int numerator1 = numerator * op2.getDenominator();
        int numerator2 = op2.getNumerator() * denominator;
        int difference = numerator1 - numerator2;//difference差的分子
        System.out.print("(" + this.toString() + ")" + " - " + "(" + op2.toString() + ")" + "=");
        return new fraction(difference, commonDenominator);//difference分子，commonDenominator分母
    }

    public fraction multiply(fraction op2)//乘法，例如(2/3)*(1/2)=(2*1)/(3*2)
    {

        int denom = denominator * op2.getDenominator();//积的分母
        int numer = numerator * op2.getNumerator();//积的分子
        System.out.print("(" + this.toString() + ")" + " * " + "(" + op2.toString() + ")" + "=");
        return new fraction(numer, denom);//numer分子，denom分母
    }

    public fraction divide(fraction op2)//除法，例如(2/3)/(1/2)=(2*2)/(3*1)
    {
        fraction op1 = op2.reciprocal();//除数取倒数，转变为乘法
        int numer = numerator * op1.getNumerator();
        int denom = denominator * op1.getDenominator();
        System.out.print("(" + this.toString() + ")" + " / " + "(" + op2.toString() + ")" + "=");
        return new fraction(numer, denom);
    }

    public boolean isLike(fraction op2) {
        return (numerator == op2.getNumerator() &&
                denominator == op2.getDenominator());
    }

    public String toString() {
        String result;

        if (numerator == 0)
            result = "0";
        else if (denominator == 1)
            result = numerator + "";
        else
            result = numerator + "/" + denominator;//输出格式：分子/分母

        return result;
    }

    private void reduce() {
        if (numerator != 0) {
            int common = gcd(Math.abs(numerator), denominator);

            numerator = numerator / common;
            denominator = denominator / common;//约分
        }
    }

    private int gcd(int num1, int num2) {
        while (num1 != num2)
            if (num1 > num2)
                num1 = num1 - num2;
            else
                num2 = num2 - num1;

        return num1;
    }

    public static fraction obj() {
        Random ran = new Random();
        return new fraction(ran.nextInt(20) - 10, ran.nextInt(20) - 10);
    }
}