java语言程序设计 第十三章 （13.17、13.18）

程序小白，希望和大家多交流，共同学习

public class Complex implements Cloneable{    private double realPart;    private double imaginaryPart;    public Complex()    {    }    public Complex(double a)    {        this(a, 0);    }    public Complex(double a, double b)    {        this.realPart = a;        this.imaginaryPart = b;    }    public double getRealPart()    {        return realPart;    }    public double getImaginaryPart()    {        return imaginaryPart;    }    public Complex add(Complex c)    {        double r = realPart + c.getRealPart();        double i = imaginaryPart + c.getImaginaryPart();        return new Complex(r, i);    }    public Complex subtract(Complex c)    {        double r = realPart - c.getRealPart();        double i = imaginaryPart - c.getImaginaryPart();        return new Complex(r, i);    }    public Complex multiply(Complex c)    {        double r = realPart * c.getRealPart() - imaginaryPart * c.getImaginaryPart();        double i = realPart * c.getImaginaryPart() + imaginaryPart * c.getRealPart();        return new Complex(r, i);    }    public Complex divide(Complex c)    {        double r = (realPart * c.getRealPart() + imaginaryPart * c.getImaginaryPart()) /             (c.getRealPart() * c.getRealPart() + c.getImaginaryPart() * c.getImaginaryPart());        double i = (realPart * c.getImaginaryPart() - imaginaryPart * c.getRealPart()) /            (c.getRealPart() * c.getRealPart() + c.getImaginaryPart() * c.getImaginaryPart());        return new Complex(r, i);    }    public double abs()    {        return Math.sqrt(realPart * realPart + imaginaryPart * imaginaryPart);    }    @Override    public String toString()    {        if (realPart == 0)        {            return imaginaryPart + "i";        }        else if (imaginaryPart == 0)        {            return realPart + "";        }        else            return realPart + " + " + imaginaryPart + "i";    }    @Override    public Object clone()    {        return new Complex(realPart, imaginaryPart);    }}

import java.util.Scanner;public class TestComplex{    public static void main(String [] args)    {        Scanner input = new Scanner(System.in);        System.out.print("Enter the first complex number : ");        double r1 = input.nextDouble();        double i1 = input.nextDouble();        Complex complex1 = new Complex(r1, i1);        System.out.print("Enter the second complex number : ");        double r2 = input.nextDouble();        double i2 = input.nextDouble();        Complex complex2 = new Complex(r2, i2);        String c1 = "(" + r1 + " + " + i1 + "i)";        String c2 = "(" + r2 + " + " + i2 + "i)";        System.out.println( c1 + " + " + c2 + " = " + complex1.add(complex2).toString());        System.out.println( c1 + " - " + c2 + " = " + complex1.subtract(complex2).toString());        System.out.println( c1 + " * " + c2 + " = " + complex1.multiply(complex2).toString());        System.out.println( c1 + " / " + c2 + " = " + complex1.divide(complex2).toString());        System.out.println( "|" + c1 + " + " + c2 + "| = " + complex1.abs());    }}

Ratioanl类请查看Java语言程序设计 第十三章 13.15

import java.math.BigInteger;public class BigAdd{    public static void main(String [] args)    {        Rational sum = new Rational();        Rational element = null;        for (int i = 1; i < 100; i++)        {            element = new Rational(new BigInteger(new Integer(i).toString()), new BigInteger(new Integer(i + 1).toString()));            sum = sum.add(element);            System.out.println("loading...");        }        System.out.println(sum);    }}