http://gist.github.com/275842

gistfile1.java

import java.io.*;

class Quadratic {
	private PrintStream jout = new PrintStream(System.out);
	private double a, b, c, delta;
	private CComplex x1 = new CComplex();
	private CComplex x2 = new CComplex();

	public Quadratic() {
		this.a = 0;
		this.b = 0;
		this.c = 0;
		this.delta = 0;
	}
	public void Solution()
	{
		this.delta = Math.pow(this.b, 2.0) - 4 * this.a * this.c;
		if ( this.delta > 0 )
		{
			this.x1.real = ((0.0 - this.b) + Math.sqrt(this.delta)) / this.a;
			this.x2.real = ((0.0 - this.b) - Math.sqrt(this.delta)) / this.a;
		}
		else if ( this.delta < 0 )
		{
			this.x1.real = (0.0 - this.b) / this.a;
			this.x2.real = this.x1.real;
			this.x1.imaginary = Math.sqrt((0 - this.delta)) / this.a;
			this.x2.imaginary = 0 - this.x1.imaginary;
		}
		else
		{
			this.x1.real = (0.0 - this.b) / this.a;
			this.x2.real = this.x1.real;
		}
	}
	public void setA(double x)
	{
		this.a = x;
	}
	public void setB(double x)
	{
		this.b = x;
	}
	public void setC(double x)
	{
		this.c = x;
	}
	public CComplex getX1()
	{
		return this.x1;
	}
	public CComplex getX2()
	{
		return this.x2;
	}
	public void Readme()
	{
		jout.printf("Compute x of formula\n");
		jout.printf("ax^2 + bx + c = 0\n");
	}
}