[C#/COMMON] 복소수 구조체

using System;

/// <summary>
/// 복소수
/// </summary>
public struct Complex
{
    //////////////////////////////////////////////////////////////////////////////////////////////////// Field
    ////////////////////////////////////////////////////////////////////////////////////////// Public

    #region Field

    /// <summary>
    /// 실수부
    /// </summary>
    private double real;

    /// <summary>
    /// 가수부
    /// </summary>
    private double imaginary;

    #endregion

    //////////////////////////////////////////////////////////////////////////////////////////////////// Property
    ////////////////////////////////////////////////////////////////////////////////////////// Static
    //////////////////////////////////////////////////////////////////////////////// Public

    #region 0 - Zero

    /// <summary>
    /// 0
    /// </summary>
    public static Complex Zero
    {
        get
        {
            return new Complex(0d, 0d);
        }
    }

    #endregion

    ////////////////////////////////////////////////////////////////////////////////////////// Instance
    //////////////////////////////////////////////////////////////////////////////// Public

    #region 실수부 - Real

    /// <summary>
    /// 실수부
    /// </summary>
    public double Real
    {
        get
        {
            return this.real;
        }
        set
        {
            this.real = value;
        }
    }

    #endregion

    #region 가수부 - Imaginary

    /// <summary>
    /// 가수부
    /// </summary>
    public double Imaginary
    {
        get
        {
            return this.imaginary;
        }
        set
        {
            this.imaginary = value;
        }
    }

    #endregion

    #region 크기 - Magnitude

    /// <summary>
    /// 크기
    /// </summary>
    public double Magnitude
    {
        get
        {
            return Math.Sqrt(this.real * this.real + this.imaginary * this.imaginary);
        }
    }

    #endregion

    #region 위상 - Phase

    /// <summary>
    /// 위상
    /// </summary>
    public double Phase
    {
        get
        {
            return Math.Atan(this.imaginary / this.real);
        }
    }

    #endregion

    #region 제곱 크기 - SquaredMagnitude

    /// <summary>
    /// 제곱 크기
    /// </summary>
    public double SquaredMagnitude
    {
        get
        {
            return (this.real * this.real + this.imaginary * this.imaginary);
        }
    }

    #endregion

    //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
    ////////////////////////////////////////////////////////////////////////////////////////// Public

    #region 생성자 - Complex(real, imaginary)

    /// <summary>
    /// 생성자
    /// </summary>
    /// <param name="real">가수부</param>
    /// <param name="imaginary">실수부</param>
    public Complex(double real, double imaginary)
    {
        this.real      = real;
        this.imaginary = imaginary;
    }

    #endregion

    #region 생성자 - Complex(complex)

    /// <summary>
    /// 생성자
    /// </summary>
    /// <param name="complex">복소수</param>
    public Complex(Complex complex)
    {
        this.real      = complex.Real;
        this.imaginary = complex.Imaginary;
    }

    #endregion

    //////////////////////////////////////////////////////////////////////////////////////////////////// Method
    ////////////////////////////////////////////////////////////////////////////////////////// Static
    //////////////////////////////////////////////////////////////////////////////// Public

    #region + 연산자 - operator+(complex1, complex2)

    /// <summary>
    /// + 연산자
    /// </summary>
    /// <param name="complex1">복소수 1</param>
    /// <param name="complex2">복소수 2</param>
    /// <returns>복소수</returns>
    public static Complex operator+(Complex complex1, Complex complex2)
    {
        return new Complex(complex1.Real + complex2.Real, complex1.Imaginary + complex2.Imaginary);
    }

    #endregion

    #region - 연산자 - operator-(complex1, complex2)

    /// <summary>
    /// 연산자 -
    /// </summary>
    /// <param name="complex1">복소수 1</param>
    /// <param name="complex2">복소수 2</param>
    /// <returns>복소수</returns>
    public static Complex operator-(Complex complex1, Complex complex2)
    {
        return new Complex(complex1.Real - complex2.Real, complex1.Imaginary - complex2.Imaginary);
    }

    #endregion

    #region * 연산자 - operator*(complex1, complex2)

    /// <summary>
    /// 연산자 *
    /// </summary>
    /// <param name="complex1">복소수 1</param>
    /// <param name="complex2">복소수 2</param>
    /// <returns>복소수</returns>
    public static Complex operator*(Complex complex1, Complex complex2)
    {
        return new Complex
        (
            complex1.Real * complex2.Real      - complex1.Imaginary * complex2.Imaginary,
            complex1.Real * complex2.Imaginary + complex1.Imaginary * complex2.Real
        );
    }

    #endregion

    #region / 연산자 - operator/(complex1, complex2)

    /// <summary>
    /// / 연산자
    /// </summary>
    /// <param name="complex1">복소수 1</param>
    /// <param name="complex2">복소수 2</param>
    /// <returns>복소수</returns>
    public static Complex operator/(Complex complex1, Complex complex2)
    {
        double divider = complex2.Real * complex2.Real + complex2.Imaginary * complex2.Imaginary;

        if(divider == 0)
        {
            throw new DivideByZeroException();
        }
            
        return new Complex
        (
            (complex1.Real * complex2.Real + complex1.Imaginary * complex2.Imaginary) / divider,
            (complex1.Imaginary * complex2.Real - complex1.Real * complex2.Imaginary) / divider
        );
    }

    #endregion

    ////////////////////////////////////////////////////////////////////////////////////////// Instance
    //////////////////////////////////////////////////////////////////////////////// Public

    #region 문자열 구하기 - ToString()

    /// <summary>
    /// 문자열 구하기
    /// </summary>
    /// <returns>문자열</returns>
    public override string ToString()
    {
        return string.Format
        (
            "{0}{1}{2}i",
            this.real,
            ((this.imaginary < 0) ? '-' : '+'),
            Math.Abs(this.imaginary)
        );
    }

    #endregion
}