设计一个表示虚数的类，需要实现其中的构造函数、toString、euqals、hashCo ...

package examination;

public class ImaginaryNumber implements Comparable<ImaginaryNumber>
{
    public ImaginaryNumber(int n, int i)
    {
        realnum = n;
        imanum = i;
    }

    public ImaginaryNumber(int n)
    {
        realnum = n;
        imanum = 0;
    }

    public String toString()
    {
        String s = realnum + "+" + imanum + "i";
        return s;
    }

    public boolean equals(ImaginaryNumber i)
    {
        if (this.realnum == i.realnum)
        {
            if (this.imanum == i.imanum)
                return true;
        }
        return false;
    }

    public int hashCode()
    {
        int h = 31;
        h = 31 * h + realnum;
        h = 31 * h + imanum;
        return h;
    }

    private int realnum;
    private int imanum;

    @Override
    public int compareTo(Imanum other)
    {

        double r = Math.sqrt(Math.pow(this.realnum, 2)
                + Math.pow(this.imanum, 2));
        double o = Math.sqrt(Math.pow(other.realnum, 2)
                + Math.pow(other.imanum, 2));
        if (r > o)
            return 1;
        if (r < o)
            return -1;
        return 0;
    }
}