编写一个java程序，实现试卷出题数学计算

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

public class MathQuiz {

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
Random random = new Random();
int score = 0;
int totalScore = 0;
int numOfQuestions = 0;

System.out.println("欢迎来到数学计算测试！");
System.out.print("请输入题目数量：");
numOfQuestions = scanner.nextInt();

for (int i = 0; i < numOfQuestions; i++) {
int num1 = random.nextInt(100);
int num2 = random.nextInt(100);
int operator = random.nextInt(4); // 0: +, 1: -, 2: *, 3: /
int answer = 0;

switch (operator) {
case 0:
System.out.print((i+1) + ". " + num1 + " + " + num2 + " = ");
answer = num1 + num2;
break;
case 1:
System.out.print((i+1) + ". " + num1 + " - " + num2 + " = ");
answer = num1 - num2;
break;
case 2:
System.out.print((i+1) + ". " + num1 + " * " + num2 + " = ");
answer = num1 * num2;
break;
case 3:
num2 = (num2 == 0) ? 1 : num2; // 避免除数为0
num1 = num1 * num2; // 为了确保结果是整数
System.out.print((i+1) + ". " + num1 + " / " + num2 + " = ");
answer = num1 / num2;
break;
}

int userAnswer = scanner.nextInt();
if (userAnswer == answer) {
System.out.println("回答正确！");
score++;
} else {
System.out.println("回答错误。正确答案是：" + answer);
}

totalScore++;
}

System.out.println("测试结束，您的得分是：" + score + " / " + totalScore);
}

}