java补充代码分数运算

以下程序实现分数的加法运算，请在此程序的基础上，实现分数的减法运算、乘法运算、除法运算，并进行测试。输入要求：整数，不考虑分母为0情况；输出要求：最简分数，分母不为1，分子不为0，分母不为0 注意输出-1/4（符号在分子）
样例输入 Copy

1 4 1 2
样例输出 Copy
3/4
-1/4
1/8
1/2

import java.util.Scanner; 

public class Main { 

       public static void main(String[] args) {         

              Fraction f1=new Fraction(1,4); 

              Fraction f2=new Fraction(1,4); 

              Fraction f3=f1.add(f2); 

              f3.print(); 

               //此处补充程序 

       } 

} 

class Fraction{ 

       int numerator; 

       int denominator; 

       Fraction(){} 

       Fraction(int n,int d){ 

              numerator=n; 

              denominator=d; 

       } 

       Fraction add(Fraction f2){ 

              Fraction f3=new Fraction(); 

              f3.numerator=numerator*f2.denominator+denominator*f2.numerator; 

              f3.denominator=denominator*f2.denominator; 

              return f3; 

       } 

       Fraction sub(Fraction f2){ //分数的减法运算 

              

       } 

       Fraction multi(Fraction f2){ //分数的乘法运算 

       } 

       Fraction divide(Fraction f2){ //分数的除法运算 




       } 

       void print(){ 

              reduction(); 

              //以下输出需要修改成符合题目要求的形式 

              System.out.println(numerator+"/"+denominator); 

       } 

       void reduction(){ //对分数进行约分，化成最简分数 

              //请补充完整。此处直接对numerator和denominator进行约分 

              //求分子分母的最大公约数，记为a 

              numerator=numerator/a; 

              denominator=denominator/a;        

       } 

} 

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Fraction f1=new Fraction(1,4);
        Fraction f2=new Fraction(1,4);
        Fraction f3=f1.add(f2);
        f3.print();
        Fraction f4=f1.sub(f2); //测试分数减法
        f4.print();
        Fraction f5=f1.multi(f2); //测试分数乘法
        f5.print();
        Fraction f6=f1.divide(f2); //测试分数除法
        f6.print();
    }
}

class Fraction{

    int numerator;
    int denominator;

    Fraction(){}

    Fraction(int n,int d){
        numerator=n;
        denominator=d;
    }

    Fraction add(Fraction f2){
        Fraction f3=new Fraction();
        f3.numerator=numerator*f2.denominator+denominator*f2.numerator;
        f3.denominator=denominator*f2.denominator;
        f3.reduction();
        return f3;
    }

    Fraction sub(Fraction f2){ //分数的减法运算
        Fraction f3=new Fraction();
        f3.numerator=numerator*f2.denominator-denominator*f2.numerator;
        f3.denominator=denominator*f2.denominator;
        f3.reduction();
        return f3;
    }

    Fraction multi(Fraction f2){ //分数的乘法运算
        Fraction f3=new Fraction();
        f3.numerator=numerator*f2.numerator;
        f3.denominator=denominator*f2.denominator;
        f3.reduction();
        return f3;
    }

    Fraction divide(Fraction f2){ //分数的除法运算
        Fraction f3=new Fraction();
        f3.numerator=numerator*f2.denominator;
        f3.denominator=denominator*f2.numerator;
        f3.reduction();
        return f3;
    }

    void print(){
        reduction();
        if(denominator == 1) //判断分数是否为整数
            System.out.println(numerator);
        else
            System.out.println(numerator+"/"+denominator);
    }

    void reduction(){ //对分数进行约分，化成最简分数
        int a = gcd(numerator,denominator); //求分子分母的最大公约数，记为a
        numerator=numerator/a;
        denominator=denominator/a;
    }

    int gcd(int a,int b){ //求最大公约数的辗转相除法
        int temp;
        while(b != 0){
            temp=b;
            b=a%b;
            a=temp;
        }
        return a;
    }
}