Java 1022，

Java 1022，

package com.lovo;
/**
 * 分数运算；
 * @author 周博
 */

import java.util.Scanner;

public class Scoremain {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		System.out.print("**** 分数计算器  ****\n");
		System.out.println("请输入第一个分数：");
		String str0 = sc.nextLine();
		char str1 = str0.charAt(0);
		int a1 = Integer.parseInt(str1+"");
		char str2 = str0.charAt(2);
		int a2 = Integer.parseInt(str2+"");
		
		System.out.println("请输入第二个分数：");
		String str4 = sc.nextLine();
		char str5 = str4.charAt(0);
		int b1 = Integer.parseInt(str5+"");
		char str6 = str4.charAt(2);
		int b2 = Integer.parseInt(str6+"");
		
		Score s1 = new Score(a1,a2);
		Score s2 = new Score(b1,b2);
		
		System.out.printf("请选择：\n");
		System.out.print("1.分数加法\n");
		System.out.print("2.分数减法\n");
		System.out.print("3.分数乘法\n");
		System.out.print("4.分数除法\n");
		System.out.print("5.分数化简\n");
		
		if(sc.hasNextInt()){
			int number = sc.nextInt();
			switch(number){
			case 1:
				System.out.println("加法："+ s1.add(s2));
				break;
			case 2:
				System.out.println("减法："+ s1.sub(s2));
				break;
			case 3:
				System.out.println("乘法："+ s1.mul(s2));
				break;
			case 4:
				System.out.println("除法："+ s1.div(s2));
				break;
			case 5:
				System.out.println("化简："+ s1.sim(b1, b2));
				break;
				default:
					System.out.print("选项错误！");
			}
			
		}else{
			System.out.print("对不起，没有该选项！");
		}
		sc.close();
	}
}

package com.lovo;

public class Score {
	private int Molecular;
	private int Denominator;
	
	/**
	 * 构造器；
	 * @param Molecular
	 * @param Denominator
	 */
	public Score(int Molecular, int Denominator) {
		this.Molecular = Molecular;
		this.Denominator = Denominator;
	}
    
	/**
	 * 加法；
	 * @param other
	 * @return
	 */
	public String add(Score other){
		int denPoi =this.Denominator*other.Denominator;     //分母*分母的积；
		int molSum = this.Molecular*other.Denominator+other.Molecular*this.Denominator; //分子+分子的和；
		return sim(molSum,denPoi); //还回化简后的分子和 and 分母积；
	}
	
	/**
	 * 减法；
	 * @param other
	 * @return
	 */
	public String sub(Score other){
		int denPoi =this.Denominator*other.Denominator;
		int molPoor = this.Molecular*other.Denominator-other.Molecular*other.Denominator;
		return sim(molPoor,denPoi);
	}
	
	/**
	 * 乘法；
	 * @param other
	 * @return
	 */
	public String mul(Score other){
		int molPio =this.Molecular*other.Molecular;
		int denPoi =this.Denominator*other.Denominator;
		return sim(molPio,denPoi);
	}
	
	/**
	 * 除法；
	 * @param other
	 * @return
	 */
	public String div(Score other){
		int molPio =this.Molecular*other.Denominator;
		int denPoi =this.Denominator*other.Molecular;
		return sim(molPio,denPoi);
	}
	
	/**
	 * 化简；
	 * 最大公约数；
	 * @param a
	 * @param b
	 * @return
	 */
	public String sim(int a,int b){
		for(int i=Math.abs(a);i>=1;i--){
			if(a%i==0 && b%i==0){
				return a/i+"/"+b/i;
			}
		}
		return a+"/"+b;
	}
}