【JAVA】猜数字

import java.util.*;

public class GN {
    public static void main(String arg[]) {
        int a = 0;// 数字标记
        int b = 0;// 位置标记
        int time = 0;// 次数
        int rdn[] = new int[5];
        Random rd = new Random();

        do {
            rdn[0] = rd.nextInt(9);
            rdn[1] = rd.nextInt(9);
            rdn[2] = rd.nextInt(9);
            rdn[3] = rd.nextInt(9);// 生成四个随机数字。
            if (rdn[0] == 0 || rdn[0] == rdn[1] || rdn[0] == rdn[2]
                    || rdn[0] == rdn[3] || rdn[1] == rdn[2] || rdn[1] == rdn[3]
                    || rdn[1] == rdn[4] || rdn[2] == rdn[3] || rdn[2] == rdn[4]
                    || rdn[3] == rdn[4])
                continue;
            else
                break;
        } while (true);

        do {
            System.out.println("请输入您所猜的数字：");
            Scanner s = new Scanner(System.in);
            int n = s.nextInt();
            String x = String.valueOf(n);
            if (n == 1)
                System.out.println(rdn[0] + "" + rdn[1] + "" + rdn[2] + ""
                        + rdn[3]);
            int num[] = new int[4];
            num[0] = n / 1000;
            num[1] = n / 100 % 10;
            num[2] = n % 100 / 10;
            num[3] = n % 10;// 处理键入的数字
            if (num[0] == 0) {
                System.out.println("输入的数字不能以零开头，请重新输入。");
            } else if (x.length() > 4 || x.length() <= 0)
                System.out.println("输入的数字不符合要求，请重新输入。");
            else if (x.length() == 4) {
                time++;
                a = 0;
                b = 0;
                for (int i = 0; i <= 3; i++) {
                    for (int j = 0; j <= 3; j++) {
                        if (num[i] == rdn[j])
                            if (i == j)
                                b++;
                            else
                                a++;

                    }
                }
                if (b != 4)
                    System.out.println("数字相同而位置不同有 " + a + " 个，位置和数字都相同有 " + b
                            + " 个");
                if (b != 4 && time > 5)
                    System.out.println("你个笨蛋，都猜" + time + "次了，还猜不对!");
            }
            if (b == 4) {
                System.out.println("恭喜你，猜对了！一共猜了" + time + "次。");
                break;
            }
        } while (true);

    }

}