Question

我正在寻找帮助创建一个模拟彩票的随机数生成器。编写生成5个随机兆数的方法的代码数字范围。其中两个必须是偶数，其余三个数字必须是奇数。使用模数运算符（％）检查数字是否为偶数或奇数。请注意，不允许重复的数字，数字应介于1到50之间。在一个单独的类中，我需要创建一个MegaBall编号，在启动时生成1-30之间的另一个随机数。

感谢任何帮助，提前致谢！

public class MegaBall {
public static void main(String[] args)
{
        int[] lottoNumber = new int[5];
    {`public class MegaBall {
public static void main(String[] args)
{
        int[] lottoNumber = new int[5];
    {
    lottoNumber[0] = (int) ((50 * Math.random()) + 1);
    lottoNumber[1] = (int) ((50 * Math.random()) + 1);
    lottoNumber[2] = (int) ((50 * Math.random()) + 1);
    lottoNumber[3] = (int) ((50 * Math.random()) + 1);
    lottoNumber[4] = (int) ((50 * Math.random()) + 1);
    }

    System.out.print("Lottery Numbers: ");
    for(int i=0; i<5; i++)
    {
        System.out.print(lottoNumber[i] + " ");
    }
}

如何获得不同的2个偶数和3个奇数？

Answer 1

拿这个，它有效：

import java.util.HashSet;
import java.util.Random;

/**
 * Created by cullycross on 2/6/15.
 */
public class Lottery {

    public static void main(String [] args) {

        LittleLottery lottery = new LittleLottery();

        lottery.showNums(lottery.getRandomNumbers());
        lottery.showNums(lottery.getRandomNum());

    }

    static class LittleLottery {

        private final int COUNT_OF_NUMS = 5;
        private final int MAX_RANDOM = 50;
        private final int MAXI_BALL = 30;
        private final Random mRandom = new Random();

        public Integer [] getRandomNumbers() {

            HashSet<Integer> nums = new HashSet<>(COUNT_OF_NUMS);

            for(int i = 0; i < COUNT_OF_NUMS; i++) {

                Integer temp;
                while (true){
                    temp = mRandom.nextInt(MAX_RANDOM) + 1;
                    if ((i + 1) % 2 == temp % 2
                            && nums.add(temp)) {

                        break;
                    }
                }
            }

            return nums.toArray(new Integer[COUNT_OF_NUMS]);
        }

        public Integer getRandomNum() {
            return mRandom.nextInt(MAXI_BALL) + 1;
        }

        public void showNums(Integer... args) {
            for(Integer i : args) {
                System.out.println(i);
            }
        }
    }
}

java随机数生成器单独的类

1 个答案: