第3次作业

要求0：

作业地址：

https://edu.cnblogs.com/campus/nenu/2016CS/homework/2266

要求1：

git仓库地址：https://git.coding.net/YUAN-FANG/f4.git

要求2：

1、 结对同学博客地址：https://www.cnblogs.com/manc762/

结对同学姓名学号：马恁超 2016011908

2、 解题思路：此次作业要考虑路径，实现四则运算，判断答题正误。要考虑加减乘除按通常四则运算规定的计算优先级，除法用整数除法，即仅保留除法运算结果的整数部分。比如8/3=2。输入表达式保证无0作为除数情况发生

3、 功能的实现

运用三个数组来存放相应的数值以及运算符号：

    public static int[] firstNum = new int[100];

    public static int[] secondNum = new int[100];

public static String[] mark = new String[]{"+","-","*","/"};

通过产生随机数来生产不同的运算式子：

   for(int i=0;i<100;i++){

      firstNum[i]= rand.nextInt(number) ;

      secondNum[i] = rand.nextInt(number);

 }

部分代码展示

        System.out.println("请输入产生四则运算的道数:");

        number = input.nextInt();

        System.out.println("产生四则运算式子:");

        for(int j=1;j<=number;j++){

            String markYun = mark[rand.nextInt(4)];

                        int answerInput = 0;

            int isFirstNum = firstNum[rand.nextInt(100)];

            int isSecondNum = secondNum[rand.nextInt(100)];

            switch(markYun){

            case "+":

                System.out.println(isFirstNum +  "+" + isSecondNum + "=" );

                answerInput = isFirstNum + isSecondNum;

                break;

            case "-":

                if(isFirstNum > isSecondNum){

                    System.out.println(isFirstNum +  "-" + isSecondNum + "=" );

                    answerInput = isFirstNum - isSecondNum;

                }

                else{

                    System.out.println(isSecondNum +  "-" + isFirstNum + "=" );

                    answerInput = isSecondNum - isFirstNum;

                }

                break;

            case "*":

                System.out.println(isFirstNum +  "*" + isSecondNum + "=" );

                answerInput = isFirstNum * isSecondNum;

                break;

            case "/":

                

                if(isSecondNum != 0){

                    System.out.println(isFirstNum +  "/" + isSecondNum + "=" );

                    answerInput = isFirstNum / isSecondNum;

                }else{

                    System.out.println(isFirstNum +  "/" + secondNum[rand.nextInt(100)]+1 + "=" );

                    answerInput = isFirstNum / isSecondNum;

                }

                break;

            }

        }

 

编程体会： 

1.基础薄弱，还需要努力学习

2.对同一个问题（即使很小的问题）从多个角度思考，能有不同的认识

3.结对编程对程序的质量有明显的提升