// Test out the Complex class with a couple of hardcoded numbers
//
// File: ComplexTest.java
// Author: Benjamin Lewis
// Last modified: Tuesday February 23, 1999

public class ComplexTest
{
  public static void main(String[] args)
  {
    Complex c1 = new Complex(4.5, 2.3);
    Complex c2 = new Complex(1.1, 7.7);
    
    System.out.println("c1:\t"+c1);
    System.out.println("c2:\t"+c2);
    System.out.println("c1+c2:\t"+Complex.add(c1,c2));
    System.out.println("c1-c2:\t"+Complex.subtract(c1,c2));
    System.out.println("c1*c2:\t"+Complex.multiply(c1,c2));
  }
}

----------------------------------------------------------

// This class implements complex numbers. Static methods for adding,
// subtracting, and multiplying two complex numbers are provided.
// Double precision floating point numbers are used for the real and
// imaginary parts.
//
// File: Complex.java
// Author: Benjamin Lewis
// Last modified: Tuesday February 23, 1999

public class Complex
{
  private double real = 0;
  private double imag = 0;

  public Complex()
  {
  }
  public Complex(double real, double imag)
  {
    this.real = real;
    this.imag = imag;
  }

  public static Complex add(Complex c1, Complex c2)
  {
    return new Complex(c1.real+c2.real, c1.imag+c2.imag);
  }

  public static Complex subtract(Complex c1, Complex c2)
  {
    return new Complex(c1.real-c2.real, c1.imag-c2.imag);
  }

  public static Complex multiply(Complex c1, Complex c2)
  {
    // (a+bi)*(c+di) = (ac-bd) + (ad+bc)i
    double real = c1.real*c2.real - c1.imag*c2.imag;
    double imag = c1.real*c2.imag + c1.imag*c2.real;
    return new Complex(real, imag);
  }

  public String toString()
  {
    // this is actually nicer than providing a "print" method.
    return new String("" + real + " + " + imag + "*i");
  }

  public void print()
  {
    // toString has been defined
    System.out.println(this);
  }
  
  // Accessor methods (not required)
  public double getRealPart()
  {
    return real;
  }
  public double getImaginaryPart()
  {
    return imag;
  }
  public void setRealPart(double real)
  {
    this.real = real;
  }
  public void setImaginaryPart(double real)
  {
    this.real = real;
  }
}