小学一二年级出题器(JAVA加减乘除)

public class AddSubMultiDivision {
    static int answerIndex = 0;
    public static void main(String[] args) {
        answerIndex = 0;

        StringBuffer stringBuffer = new StringBuffer();
        StringBuffer stringBuffer1 = new StringBuffer();


        stringBuffer.append("rnn" + "Leve1" + "rnn");
        stringBuffer1.append("rnn" + "Leve1" + "rnn");
        addAndSub(10, 20, stringBuffer, stringBuffer1);


        stringBuffer.append("rnn" + "Leve2" + "rnn");
        stringBuffer1.append("rnn" + "Leve2" + "rnn");
        addAndSub(20, 50, stringBuffer, stringBuffer1);


        stringBuffer.append("rnn" + "Leve3" + "rnn");
        stringBuffer1.append("rnn" + "Leve3" + "rnn");
        addAndSub(100, 50, stringBuffer, stringBuffer1);


        stringBuffer.append("rnn" + "Leve4" + "rnn");
        stringBuffer1.append("rnn" + "Leve4" + "rnn");
        addAndSub(1000, 50, stringBuffer, stringBuffer1);


        stringBuffer.append("rnn" + "Leve5" + "rnn");
        stringBuffer1.append("rnn" + "Leve5" + "rnn");
        multiAndDivision(50, 10, stringBuffer, stringBuffer1);

        System.out.println(stringBuffer.toString());
        System.out.println(stringBuffer1.toString());
    }

    
    private static void addAndSub(int max, int count, StringBuffer stringBuffer, StringBuffer stringBuffer1) {
        for (int i = 0; i < count; i++) {
            for (int j = 0; j < 4; j++) {
                if (j % 2 == 0) {
                    int number = (int) (Math.random() * max + 1);
                    int number1 = (int) (Math.random() * max + 1);
                    if (number > number1) {
                        String str = number + " -  " + number1 + " = ";
                        stringBuffer.append(str);
                        answerIndex++;
                        stringBuffer1.append(answerIndex + "、" + (number - number1));
                    } else {
                        String str = number1 + " -  " + number + " = ";
                        stringBuffer.append(str);
                        answerIndex++;
                        stringBuffer1.append(answerIndex + "、" + (number1 - number));
                    }
                    stringBuffer.append("             ");
                    stringBuffer1.append("    ");
                } else {
                    int number = (int) (Math.random() * max + 1);
                    int number1 = (int) (Math.random() * max + 1);
                    String str = number + " + " + number1 + " = ";
                    stringBuffer.append(str);
                    answerIndex++;
                    stringBuffer1.append(answerIndex + "、 " + (number1 + number));
                    stringBuffer.append("             ");
                    stringBuffer1.append("     ");
                }
            }
            stringBuffer.append("rn");
//            stringBuffer1.append("rn");
        }
        stringBuffer1.append("rn");
    }

    
    private static void multiAndDivision(int max, int count, StringBuffer stringBuffer, StringBuffer stringBuffer1) {
        for (int i = 0; i < count; i++) {
            for (int j = 0; j < 4; j++) {
                int number = (int) (Math.random() * max + 1);
                int number1 = (int) (Math.random() * max + 1);
                if (j % 2 == 0) {
                    if (number > number1 && number % number1 == 0) {
                        String str = number + " / " + number1 + " =     ";
                        stringBuffer.append(str);
                        answerIndex++;
                        stringBuffer1.append(answerIndex + "、" + (number / number1));
                    } else {
                        boolean flage = false;
                        for (int k = 0; k < 50000; k++) {
                            number = (int) (Math.random() * max + 1);
                            number1 = (int) (Math.random() * max + 1);
                            if ((number > number1) && (number % number1 == 0)) {
                                flage = true;
                                break;
                            }
                        }
                        if (flage) {
                            String str = number + " / " + number1 + " =     ";
                            stringBuffer.append(str);
                            answerIndex++;
                            stringBuffer1.append(answerIndex + "、" + (number / number1));
                        }
                    }

                } else {
                    String str = number + " X " + number1 + " =     ";
                    stringBuffer.append(str);
                    answerIndex++;
                    stringBuffer1.append(answerIndex + "、" + (number * number1));
                }

                stringBuffer.append("             ");
                stringBuffer1.append("     ");
            }
            stringBuffer.append("rn");

        }
        stringBuffer1.append("rn");
    }
}