10月14日

在原有代码的基础上添加了年级分类

package guv;

import java.util.Random;
import java.util.Scanner;
import java.time.Duration;
import java.time.Instant;

class ArithmeticGenerator {
protected Random random;
protected Scanner scanner;
protected int correctCount;
protected int wrongCount;
protected int n;
protected int max = 30;
protected int totalTimeLimitSeconds = 60;
protected Instant startTime;
protected Instant endTime;

public ArithmeticGenerator() {
    random = new Random();
    scanner = new Scanner(System.in);
    correctCount = 0;
    wrongCount = 0;
    startTime = Instant.now();
    endTime = startTime.plusSeconds(totalTimeLimitSeconds);
}

public void generateAndCheckAnswer() {
    // 需要在子类中实现具体的生成题目和检查答案逻辑
}

public void displayResult() {
    double totalQuestions = 30;
    double correctRate = correctCount / totalQuestions * 100;
    System.out.println("你答对了 " + correctCount + " 道题。");
    System.out.println("你答错了 " + wrongCount + " 道题。");
    System.out.println("正确率为：" + correctRate + "%");
}

}

class SecondGradeArithmeticGenerator extends ArithmeticGenerator {

public void generateAndCheckAnswer() {
    for (int i = 0; i < max; i++) {
        int num1, num2, result;
        String operator;

        num1 = random.nextInt(100) + 1;
        num2 = random.nextInt(100) + 1;
        int operatorIndex = random.nextInt(4);
        switch (operatorIndex) {
            case 0:
                operator = "+";
                result = num1 + num2;
                break;
            case 1:
                num1 = random.nextInt(100) + 1;
                num2 = random.nextInt(num1) + 1;
                operator = "-";
                if ((num1 - num2) < 0) {
                    i--;
                    continue;
                }
                result = num1 - num2;
                break;
            case 2:
                num1 = random.nextInt(100) + 1;
                num2 = random.nextInt(100) + 1;
                operator = "*";
                result = num1 * num2;
                break;
            default:
                operator = "/";
                if (num2 == 0 || num1 % num2!= 0) {
                    i--;
                    continue;
                }
                result = num1 / num2;
                break;
        }

        System.out.println(num1 + " " + operator + " " + num2 + " = ");

        int userAnswer;
        try {
            userAnswer = scanner.nextInt();
        } catch (Exception e) {
            userAnswer = -1;
        }

        if (userAnswer == result) {
            correctCount++;
        } else {
            wrongCount++;
        }

        Instant currentTime = Instant.now();
        if (currentTime.isAfter(endTime)) {
            break;
        }
    }
}

}

class ThirdGradeArithmeticGenerator extends SecondGradeArithmeticGenerator {

public void generateAndCheckAnswer() {
    for (int i = 0; i < max; i++) {
        int num1, num2, num3, num4;
        int result;
        String operator;

        num1 = random.nextInt(1000) + 1;
        num2 = random.nextInt(1000) + 1;
        num3 = random.nextInt(1000) + 1;
        num4 = random.nextInt(1000) + 1;

        int operatorIndex = random.nextInt(4);
        switch (operatorIndex) {
            case 0:
                operator = "+";
                result = num1 + num2 + num3 + num4;
                break;
            case 1:
                operator = "-";
                result = num1 - num2 - num3 - num4;
                if (result < 0) {
                    i--;
                    continue;
                }
                break;
            case 2:
                operator = "*";
                result = num1 * num2 * num3 * num4;
                break;
            default:
                operator = "/";
                if (num2 == 0 || num3 == 0 || num4 == 0 || num1 % num2 % num3 % num4!= 0) {
                    i--;
                    continue;
                }
                result = num1 / num2 / num3 / num4;
                break;
        }

        System.out.println(num1 + " " + operator + " " + num2 + " " + operator + " " + num3 + " " + operator + " " + num4 + " = ");

        int userAnswer;
        try {
            userAnswer = scanner.nextInt();
        } catch (Exception e) {
            userAnswer = -1;
        }

        if (userAnswer == result) {
            correctCount++;
        } else {
            wrongCount++;
        }

        Instant currentTime = Instant.now();
        if (currentTime.isAfter(endTime)) {
            break;
        }
    }
}

}

class FourthGradeArithmeticGenerator extends ThirdGradeArithmeticGenerator {

public void generateAndCheckAnswer() {
    for (int i = 0; i < max; i++) {
        int num1, num2, num3, num4, num5 = 0;
        int result;
        String operator;

        num1 = random.nextInt(1000) + 1;
        num2 = random.nextInt(1000) + 1;
        num3 = random.nextInt(1000) + 1;
        num4 = random.nextInt(1000) + 1;

        int operatorIndex = random.nextInt(4);
        switch (operatorIndex) {
            case 0:
                operator = "+";
                result = num1 + num2 + num3 + num4 + num5;
                break;
            case 1:
                operator = "-";
                result = num1 - num2 - num3 - num4 - num5;
                if (result < 0) {
                    i--;
                    continue;
                }
                break;
            case 2:
                operator = "*";
                result = num1 * num2 * num3 * num4 * num5;
                break;
            default:
                operator = "/";
                if (num2 == 0 || num3 == 0 || num4 == 0 || num5 ==0 || num1 % num2 % num3 % num4 % num5!= 0) {
                    i--;
                    continue;
                }
                result = num1 / num2 / num3 / num4 /num5;
                break;
        }

        System.out.println(num1 + " " + operator + " " + num2 + " " + operator + " " + num3 + " " + operator + " " + num4 + 
        		 " " +operator + " " + num5+" = ");

        int userAnswer;
        try {
            userAnswer = scanner.nextInt();
        } catch (Exception e) {
            userAnswer = -1;
        }

        if (userAnswer == result) {
            correctCount++;
        } else {
            wrongCount++;
        }

        Instant currentTime = Instant.now();
        if (currentTime.isAfter(endTime)) {
            break;
        }
    }
}

}

public class RandomArithmeticGenerator {
public static void main(String[] args) {
System.out.println("请选择年级（1 表示一年级，2 表示二年级，3 表示三年级）：");
Scanner scanner = new Scanner(System.in);
int grade = scanner.nextInt();

    ArithmeticGenerator generator;
    if (grade == 2) {
        generator = new SecondGradeArithmeticGenerator();
    } else if (grade == 3) {
        generator = new ThirdGradeArithmeticGenerator();
    } else {
        generator = new ArithmeticGenerator();
    }

    generator.generateAndCheckAnswer();
    generator.displayResult();

    scanner.close();
}

}