北邮java oj 1052 问题 B: 复数

题目描述

编写复数类，该类至少包括计算复数的加法、减法、乘法、除法的方法。
编写ComplexDivException类，该类继承Exception类，且至少包含两个数据成员，一个为错误代码，一个为错误信息。当复数类除数为0时要抛出该异常。
编写测试类，测试以上两个类。





 

输入

第一行为一个字符串，只可能为add,sub,mul,div四个字符串之一。依次代表本次测试执行加法、减法、乘法和除法。
第二行为一个整数n(0<n<100)，代表共n组测试用例。
后边为n行，每行均为4个用空格分隔的浮点数，依次参与运算的两个复数c1、c2。第一个数代表c1的实部，第二个数代表c1的虚部，第三个数代表c2的实部，第四个数代表c2的虚部。

输出

若干行，通常一行对应输入的一行，为c1加或减或乘或除以c2的结果（保留一位小数，具体格式见样例），如果除法的除数为0，则输出两行对应输入的一行，这两行的内容为（注意空格）：
Error No : 1001
Error Message : Divide by zero.


前边的1001为错误代码，后边Divide by zero. 为错误信息。
注意输出时建议采用String的格式化，或printf的格式化，不建议采用DecimalFormat。

样例输入 Copy

add
6
1 1 -1 -1
90.9 68.8 60.3 79.3
4.3 65.4 69.2 -49.7
-8.33 -1.14 4.2 1.62
3.7 1.86 -5.46 9.22
15.1 -19.6 2.2 -3.73

样例输出 Copy

0.0+0.0i
151.2+148.1i
73.5+15.7i
-4.1+0.5i
-1.8+11.1i
17.3-23.3i

import java.util.Scanner;

public class  ComplexDivExceptionTest{

    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);

        String operation = scanner.nextLine();

        int n = scanner.nextInt();

        scanner.nextLine();

        for (int i = 0; i < n; i++) {

            String[] input = scanner.nextLine().split(" ");

            double real1 = Double.parseDouble(input[0]);

            double imag1 = Double.parseDouble(input[1]);

            double real2 = Double.parseDouble(input[2]);

            double imag2 = Double.parseDouble(input[3]);

            Complex c1 = new Complex(real1, imag1);

            Complex c2 = new Complex(real2, imag2);

            try {

                Complex result;

                switch (operation) {

                    case "add":

                        result = c1.add(c2);

                        System.out.println(result);

                        break;

                    case "sub":

                        result = c1.sub(c2);

                        System.out.println(result);

                        break;

                    case "mul":

                        result = c1.mul(c2);

                        System.out.println(result);

                        break;

                    case "div":

                        result = c1.div(c2);

                        System.out.println(result);

                        break;

                }

            } catch (ComplexDivException e) {

                System.out.println("Error No : " + e.getErrorCode());

                System.out.println("Error Message : " + e.getErrorMessage());

            }

        }

    }

}

class Complex {

    private double real;

    private double imag;

    public Complex(double real, double imag) {

        this.real = real;

        this.imag = imag;

    }

    public Complex add(Complex other) {

        return new Complex(this.real + other.real, this.imag + other.imag);

    }

    public Complex sub(Complex other) {

        return new Complex(this.real - other.real, this.imag - other.imag);

    }

    public Complex mul(Complex other) {

        double newReal = this.real * other.real - this.imag * other.imag;

        double newImag = this.real * other.imag + this.imag * other.real;

        return new Complex(newReal, newImag);

    }

    public Complex div(Complex other) throws ComplexDivException {

        double denominator = other.real * other.real + other.imag * other.imag;

        if (denominator == 0) {

            throw new ComplexDivException(1001, "Divide by zero.");

        }

        double newReal = (this.real * other.real + this.imag * other.imag) / denominator;

        double newImag = (this.imag * other.real - this.real * other.imag) / denominator;

        return new Complex(newReal, newImag);

    }

    @Override

    public String toString() {

        if (imag >= 0) {

            return String.format("%.1f+%.1fi", real, imag);

        } else {

            return String.format("%.1f%.1fi", real, imag);

        }

    }

}

 class ComplexDivException extends Exception {

    private int errorCode;

    private String errorMessage;

    public ComplexDivException(int errorCode, String errorMessage) {

        this.errorCode = errorCode;

        this.errorMessage = errorMessage;

    }

    public int getErrorCode() {

        return errorCode;

    }

    public String getErrorMessage() {

        return errorMessage;

    }

}