用java具体代码实现分数(即有理数)四则运算

1，背景

Java老师布置了一个关于有理数运算的题目，因为参考书上有基本代码，所以自己主要是对书上代码做了一点优化，使其用户交互性更加友好以及代码封装性更强

2，说明:

分数也称作有理数，是我们很熟悉的一种数。有时希望程序能对分数进行四则运算，而且两个分数四则运算的结果仍然是分数。下面是具体实现

3，java代码具体实现

3.1 运算类封装

package Rational;

import java.util.StringTokenizer;

/**

 * @author sunkun

 * 分数四则运算

 */

public class Calculator {

	int numerator;  // 分子

	int denominator; // 分母

	Calculator(){

	}

	Calculator(int a,int b){

		if(a == 0){

			numerator = 0;

			denominator = 1;

		}

		else{

			setNumeratorAndDenominator(a,b);

		}

	}

	void setNumeratorAndDenominator(int a, int b){  // 设置分子和分母

		int c = f(Math.abs(a),Math.abs(b));         // 计算最大公约数

		numerator = a / c;

		denominator = b / c;

		if(numerator<0 && denominator<0){

			numerator = - numerator;

			denominator = - denominator;

		}

	}

	int getNumerator(){

		return numerator;

	}

	int getDenominator(){

		return denominator;

	}

	int f(int a,int b){  // 求a和b的最大公约数

		if(a < b){

			int c = a;

			a = b;

			b = c;

		}

		int r = a % b;

		while(r != 0){

			a = b;

			b = r;;

			r = a % b;

		}

		return b;

	}

	Calculator add(Calculator r){  // 加法运算

		int a = r.getNumerator();

		int b = r.getDenominator();

		int newNumerator = numerator * b + denominator * a;

		int newDenominator = denominator * b;

		Calculator result = new Calculator(newNumerator,newDenominator);

		return result;

	}

	Calculator sub(Calculator r){  // 减法运算

		int a = r.getNumerator();

		int b = r.getDenominator();

		int newNumerator = numerator * b - denominator * a;

		int newDenominator = denominator * b;

		Calculator result = new Calculator(newNumerator,newDenominator);

		return result;

	} 

	Calculator muti(Calculator r){ // 乘法运算

		int a = r.getNumerator();

		int b = r.getDenominator();

		int newNumerator = numerator * a;

		int newDenominator = denominator * b;

		Calculator result = new Calculator(newNumerator,newDenominator);

		return result;

	}

	Calculator div(Calculator r){  // 除法运算

		int a = r.getNumerator();

		int b = r.getDenominator();

		int newNumerator = numerator * b;

		int newDenominator = denominator * a;

		Calculator result = new Calculator(newNumerator,newDenominator);

		return result;

	}

	// 封装了具体运算，主要为对输入进行转换，对输出封装

	public static void compute(String data1,String operation,String data2){

		StringTokenizer fenxi = new StringTokenizer(data1,"/");

	    int data1_1 = Integer.parseInt(fenxi.nextToken());

	    int data1_2 = Integer.parseInt(fenxi.nextToken());

		fenxi = new StringTokenizer(data2,"/");

	    int data2_1 = Integer.parseInt(fenxi.nextToken());

	    int data2_2 = Integer.parseInt(fenxi.nextToken());

		Calculator r1 = new Calculator(data1_1,data1_2);

		Calculator r2 = new Calculator(data2_1,data2_2);

		Calculator result;

		int a,b;

		if(operation.equals("+")){

 			result = r1.add(r2);

			a = result.getNumerator();

 			b = result.getDenominator();

			System.out.println(data1+" "+operation+" " +data2+" = " + a + "/" + b);

		}

		if(operation.equals("-")){

 			result = r1.sub(r2);

			a = result.getNumerator();

 			b = result.getDenominator();

			System.out.println(data1+" "+operation+" " +data2+" = " + a + "/" + b);

		}

		if(operation.equals("*")){

 			result = r1.muti(r2);

			a = result.getNumerator();

 			b = result.getDenominator();

			System.out.println(data1+" "+operation+" " +data2+" = " + a + "/" + b);

		}

		if(operation.equals("/")){

 			result = r1.div(r2);

			a = result.getNumerator();

 			b = result.getDenominator();

			System.out.println(data1+" "+operation+" " +data2+" = " + a + "/" + b);

		}

	}

}

3.2 测试类

package Rational;

import java.util.Scanner;

/**

 * @author sunkun

 * 为了测试分数四则运算

 * */

public class TestCal {

	public static void main(String[] args) {

		// TODO Auto-generated method stub

		// 用户输入两分数和运算符

		Scanner input = new Scanner(System.in);

		System.out.println("请用户输入第一个分数(格式a/b)");

		String data1 = input.next();

		System.out.println("请用户输入要进行运算的运算符(+-*/)");

		String operation = input.next();

		System.out.println("请用户输入第二个分数(格式c/d)");

		String data2 = input.next();

		// 根据用户输入进行具体运算

		Calculator cal = new Calculator();

		System.out.println("运算结果为:");

		cal.compute(data1, operation, data2);

//	  }

	}

}