结对编程——四则运算

package com.fancy.exam;

import java.util.Random;

public class Test {
    //一道四则运算题
    private  int number1;
    private  int number2;
    private String sig;
    private int result;
    private  String[] signal = {"+","-","*","/"}; 
    
    public Test(){
        Random rand = new Random();
        int temp = rand.nextInt(4);
        this.sig = signal[temp];
        this.number1 = rand.nextInt(100);
        this.number2 = rand.nextInt(100);
        if(this.sig.equals("/")){
            if(this.number2 != 0){        //合法的除法运算
                while(this.number1%this.number2!=0)
                {
                    this.number1 = rand.nextInt(100);
                }
            }else{        //除数为零
                this.number2 = rand.nextInt(100);
            }
        }
        switch(this.sig){
        case "+":
            this.result = this.number1 + this.number2;
            break;
        case "-":
            this.result = this.number1 - this.number2;
            break;
        case "*":
            this.result = this.number1 * this.number2;
            break;
        case "/":
            this.result = this.number1 / this.number2;
            break;
        }
        
    }
    
    
    public int getNumber1() {
        return number1;
    }


    public void setNumber1(int number1) {
        this.number1 = number1;
    }


    public int getNumber2() {
        return number2;
    }


    public void setNumber2(int number2) {
        this.number2 = number2;
    }


    public String getSig() {
        return sig;
    }


    public void setSig(String sig) {
        this.sig = sig;
    }


    public int getResult() {
        return result;
    }


    public void setResult(int result) {
        this.result = result;
    }


    public void show(){
        System.out.print(this.number1 + " " + this.number2 + " = " );
    }
}

package com.fancy.exam;

public class Tests {
    //习题集类
    private Test tests[];
    private int count;        //习题数目
    
    public Tests(int count){
        if(count>0){
            this.count = count;
        }
        tests = new Test[count];
        for(int i = 0;i<count;i++)
            tests[i] = new Test();
    }
    
    public void printTests(){    //打印习题
        for(int i=0;i<count;i++){
            System.out.print(tests[i].getNumber1() + " " + tests[i].getSig() + " " + tests[i].getNumber2() + " =\t   ");
            if((i+1)%5==0)
                System.out.println();
        }
    }
    
    public void printAnswers(){   //打印答案
        System.out.println("答案如下");
        for(int i=0;i<count;i++){
            System.out.print(tests[i].getNumber1() + " " + tests[i].getSig() + " " + tests[i].getNumber2() + " = " + tests[i].getResult() + "       \t");
            if((i+1)%5==0)
                System.out.println();
        }
    }
}

package com.fancy.exam;

import java.util.Random;
import java.util.Scanner;

public class Tester {
     //测试类
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        Scanner input = new Scanner(System.in);
        int count;
        System.out.print("请输入题目数量：");
        count = input.nextInt();
        Tests tests = new Tests(count);
        tests.printTests();
        System.out.println("是否打印答案？是：Y/y 不，直接退出：N/n");
        String choice = input.next();
        if(choice.equals("Y") || choice.equals("y")){
            tests.printAnswers();
        }else{
            System.out.println("谢谢使用，再见。");
        }
        input.close();
    }

}