ComplexNumber.java

package com.example.task03;

public class ComplexNumber {
    private final double real;
    private final double imaginary;

    public ComplexNumber(double real, double imaginary) {
        this.real = real;
        this.imaginary = imaginary;
    }

    public ComplexNumber add(ComplexNumber other) {
        return new ComplexNumber(
                this.real + other.real,
                this.imaginary + other.imaginary
        );
    }

    public ComplexNumber multiply(ComplexNumber other) {
        double newReal = this.real * other.real - this.imaginary * other.imaginary;
        double newImaginary = this.real * other.imaginary + this.imaginary * other.real;
        return new ComplexNumber(newReal, newImaginary);
    }

    @Override
    public String toString() {
        if (imaginary >= 0) {
            return String.format("%.2f + %.2fi", real, imaginary);
        } else {
            return String.format("%.2f - %.2fi", real, Math.abs(imaginary));
        }
    }
}