Question

我在Java做了一个程序，这本质上是一个数学测验，它根据用户输入随机生成简单的数学问题。现在，我正在自学C++，我只是想知道，基于效率和组织，转换这个程序的最佳方法是什么。例如，我的方法应该是类，是否应该保留在一个类中，等等。任何有关这方面的帮助将非常感谢！这是我目前的Java代码

public class MathQuiz {
Scanner s = new Scanner(System.in);

int numberOne;
int numberTwo;
int actualSolution;
int userSolution;
int numberOfQuestions;
int counter = 1;
int temp;
int randomOperation;
int totalCorrect;
int totalIncorrect;
long startTime;
long endTime;
long totalTime;
double percent;
String operation;
String done;

public void mathQuizzer(){
    System.out.println("Welcome to Math Quiz!");
    System.out.println("What kind of questions would you like to answer?");
    System.out.println("Enter + for Addition");
    System.out.println("Enter - for Subtraction");
    System.out.println("Enter * for Multiplication");
    System.out.println("Enter / for Division");
    System.out.println("Enter m for Mix");
    operation = s.next();
    System.out.println("How many questions would you like to answer? ");
    numberOfQuestions = s.nextInt();
    System.out.println();
    startTime = System.currentTimeMillis();
    while(counter <= numberOfQuestions){

        if(operation.equals("+")){
            System.out.println("Question " + counter + ":");
            createAdditionEquation();
            checkSolution();
            counter++;
        }
        else if(operation.equals("-")){
            System.out.println("Question " + counter + ":");
            createSubtractionEquation();
            checkSolution();
            counter++;
        }
        else if(operation.equals("*")){
            System.out.println("Question " + counter + ":");
            createMultiplicationEquation();
            checkSolution();
            counter++;
        }
        else if(operation.equals("/")){
            System.out.println("Question " + counter + ":");
            createDivisionEquation();
            checkSolution();
            counter++;
        }
        else if (operation.equals("m")){
            System.out.println("Question " + counter + ":");
            createMixEquation();
            checkSolution();
            counter++;
        }
        else{
            System.out.println("Sorry invalid operation");
            System.exit(0);
        }
    }
    endTime = System.currentTimeMillis();
    report();
}

public void createAdditionEquation(){
    numberOne = (int)(Math.random() * (100 + 1));
    numberTwo = (int)(Math.random() * (100 + 1));
    actualSolution = numberOne + numberTwo;

    System.out.println(numberOne + " + " + numberTwo + "= ?");
}

public void createSubtractionEquation(){
    numberOne = (int)(Math.random() * (100 + 1));
    numberTwo = (int)(Math.random() * (100 + 1));
    if(numberOne >= numberTwo){
        actualSolution = numberOne - numberTwo;
    }
    else{
        numberOne = temp;
        numberOne = numberTwo;
        numberTwo = temp;
        actualSolution = numberOne - numberTwo;
    }

    System.out.println(numberOne + " - " + numberTwo + "= ?");
}

public void createMultiplicationEquation(){
    numberOne = (int)(Math.random() * (10 + 1));
    numberTwo = (int)(Math.random() * ((20 - 1) + 1));
    actualSolution = numberOne * numberTwo;

    System.out.println(numberOne + " * " + numberTwo + "= ?");
}

public void createDivisionEquation(){
    numberOne = (int)(Math.random() * (100 + 1));
    numberTwo = (int)(1 +(Math.random() * (10 - 1)));

    if((numberOne >= numberTwo) && (numberOne%numberTwo == 0)){
        System.out.println(numberOne + " / " + numberTwo + "= ?");
        actualSolution = numberOne / numberTwo;
    }
    else{
        createDivisionEquation();
    }
}

public void createMixEquation(){
    randomOperation = (int)(Math.random() * (5 - 1));
    System.out.println("Random Operation: " + randomOperation);
    if(randomOperation == 0){
        createAdditionEquation();
    }
    else if(randomOperation == 1){
        createSubtractionEquation();
    }
    else if(randomOperation == 2){
        createMultiplicationEquation();
    }
    else
        createDivisionEquation();
}

public void checkSolution(){

    System.out.println("Answer = ");
    userSolution = s.nextInt();
    System.out.println();
    if(userSolution == actualSolution){
        System.out.println("Correct!");
        System.out.println("#########################");
        System.out.println();
        totalCorrect++;
    }
    else if(userSolution != actualSolution){
        System.out.println("Sorry, wrong answer. The correct solution is: " + actualSolution);
        System.out.println("#########################");
        System.out.println();
        totalIncorrect++;
    }

}

public void report(){
    percent = ((double) totalCorrect / numberOfQuestions) * 100;
    totalTime = (endTime - startTime) / 1000;
    System.out.println("Report:");
    System.out.println("Questions Answered: " + numberOfQuestions);
    System.out.println("Total Correct: " + totalCorrect);
    System.out.println("Total Incorrect: " + totalIncorrect);
    System.out.println("Percent: " + percent + "%");
    System.out.println("Time taken: " + totalTime + " seconds");
}

}

应该注意的是，我知道这个程序没有优化，暂时我也没关系

Answer 1

这是关于程序设计的。如果不考虑当前程序的优点（请查看code review），不论语言如何，优秀的OO设计都是好的设计而坏的设计是坏的设计。

Answer 2

保持尽可能接近Java。它使用简单的方法，可以将1：1翻译成C ++。要改变设计，可以在之后完成，特别是如果你是C ++的新手。

没有像Java泛型/ C ++模板那样的技术转变。

Answer 3

扩展我原来的评论以及其他人在此发布的答案......

如果您正在尝试自学C ++，并且您已经了解Java，那么这两者非常相似。因此，根据您对Java的了解，自学C ++。

您知道如何在Java中处理IO。查找一些文档并开始用C ++练习IO，它有点不同。

您知道如何处理Java中的方法，将其与C ++进行比较（它们几乎相同）。

但另一方面，如果你想关注效率，组织或优化，你应该从你最熟悉的语言开始。就目前情况而言，或者至少在你提出问题的方式上，你似乎试图在一个单一的范围内完成这两个目标，当选择其中一个并且关注那个目标时要好得多。。如果您只是复制＆amp;将代码粘贴并修复了Java和C ++之间的语法差异，代码的C ++版本基本上与代码的Java版本完全一样有效，优化。

C ++设计建议

3 个答案: