实现猜数游戏

生成随机数的方法：Random rd = new random(); 

主代码如下：

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

public class Day_01 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Random rd = new Random();
        boolean isFlag = true;
        String Details = "进行猜数，如果正确游戏结束.";
        String Details1 = "如果错误，继续猜并告知猜大了还是小了";
        while (isFlag) {
            System.out.println("-------欢迎来到猜数游戏-------");
            System.out.println("-----------请选择难度--------");
            System.out.println("          0.规     则");
            System.out.println("          1.简     单");
            System.out.println("          2.困     难");
            System.out.println("          3.地     狱");
            System.out.println("          4.退     出");
            System.out.print("         请选择(1-4)：");
            char selection = Utility1.readMenuSelection();
            switch (selection){
                case '0':
                    System.out.println("-------------规     则-------------");
                    System.out.println(Details);
                    System.out.println(Details1);
                    System.out.println("--------------------------------\n");
                    break;
                case '1':
                    System.out.println("-------------简     单-------------");
                    while (true) {
                        int count = 0;
                        int numbers = rd.nextInt(101) + 1;
                        System.out.println(numbers);
                        for (int i = 0; i < 20; i++) {
                            count++;
                            System.out.println("请输入你的数：");
                            int num = sc.nextInt();

                            if (num == numbers) {
                                if (count > 0 && count <= 3) {
                                    System.out.println("恭喜你获得一等奖");
                                    System.out.println("退出请输入101，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==101)
                                        break;;
                                } else if (count > 3 && count <= 8) {
                                    System.out.println("恭喜你获得二等奖");
                                    System.out.println("退出请输入101，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==101)
                                        break;;
                                } else if (count > 8 && count <= 12) {
                                    System.out.println("恭喜你获得三等奖");
                                    System.out.println("退出请输入101，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==101)
                                        break;;
                                } else {
                                    System.out.println("恭喜你获得参与奖");
                                    System.out.println("退出请输入101，请输入：");
                                    int sr =sc.nextInt();
                                    if (num==101)
                                        break;;
                                }
                            } else if (num > numbers && num <= 100) {
                                System.out.println("猜大了");
                            } else if (num>101) {
                                System.out.println("请输入1~100之间的数");
                                count--;
                            } else {
                                System.out.println("猜小了");
                            }
                        }
                            break;

                    }
                case '2':
                    System.out.println("-------------困     难-------------");
                    while (true) {
                        int count = 0;
                        int numbers = rd.nextInt(1001) + 1;
                        System.out.println(numbers);
                        for (int i = 0; i < 100; i++) {
                            count++;
                            System.out.println("请输入你的数：");
                            int num = sc.nextInt();

                            if (num == numbers) {
                                if (count > 0 && count <= 15) {
                                    System.out.println("恭喜你获得一等奖");
                                    System.out.println("退出请输入1001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==1001)
                                        break;;
                                } else if (count > 15 && count <= 45) {
                                    System.out.println("恭喜你获得二等奖");
                                    System.out.println("退出请输入1001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==1001)
                                        break;;
                                } else if (count > 45 && count <= 75) {
                                    System.out.println("恭喜你获得三等奖");
                                    System.out.println("退出请输入1001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==1001)
                                        break;;
                                } else {
                                    System.out.println("恭喜你获得参与奖");
                                    System.out.println("退出请输入1001，请输入：");
                                    int sr =sc.nextInt();
                                    if (num==1001)
                                        break;;
                                }
                            } else if (num > numbers && num <= 1000) {
                                System.out.println("猜大了");
                            } else if (num>1001) {
                                System.out.println("请输入1~100之间的数");
                                count--;
                            } else {
                                System.out.println("猜小了");
                            }
                        }
                        break;

                    }
                    break;
                case '3':
                    System.out.println("-------------困     难-------------");
                    while (true) {
                        int count = 0;
                        int numbers = rd.nextInt(10001) + 1;
                        System.out.println(numbers);
                        for (int i = 0; i < 500; i++) {
                            count++;
                            System.out.println("请输入你的数：");
                            int num = sc.nextInt();

                            if (num == numbers) {
                                if (count > 0 && count <= 15) {
                                    System.out.println("恭喜你获得一等奖");
                                    System.out.println("退出请输入10001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==10001)
                                        break;;
                                } else if (count > 15 && count <= 30) {
                                    System.out.println("恭喜你获得二等奖");
                                    System.out.println("退出请输入10001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==10001)
                                        break;;
                                } else if (count > 30 && count <= 60) {
                                    System.out.println("恭喜你获得三等奖");
                                    System.out.println("退出请输入10001，请输入：");
                                    int sr =sc.nextInt();
                                    if (sr==10001)
                                        break;;
                                } else {
                                    System.out.println("恭喜你获得参与奖");
                                    System.out.println("退出请输入10001，请输入：");
                                    int sr =sc.nextInt();
                                    if (num==10001)
                                        break;;
                                }
                            } else if (num > numbers && num <= 10000) {
                                System.out.println("猜大了");
                            } else if (num>10001) {
                                System.out.println("请输入1~100之间的数");
                                count--;
                            } else {
                                System.out.println("猜小了");
                            }
                        }
                        break;

                    }
                    break;
                case '4':
                    System.out.print("确认是否退出(Y/N)：");
                    char isExit = Utility1.readConfirmSelection();
                    if(isExit == 'Y'){
                        isFlag = false;
                    }
                    break;
            }
        }
    }
}

调用的方法的代码：

import java.util.Scanner;

public class Utility1 {
    private static Scanner sc = new Scanner(System.in);
    public static char readMenuSelection(){
        char c;
        for(; ; ){
            String str = readKeyBoard(1);
            c = str.charAt(0);
            if(c != '0' && c != '1' && c != '2' && c != '3' && c != '4'){
                System.out.print("选择错误，请重新输入");
            }else break;
        }
        return c;
    }
    public static char readConfirmSelection(){
        char c;
        for(; ; ){
            String str = readKeyBoard(1).toUpperCase();
            c = str.charAt(0);
            if(c == 'Y' || c == 'N'){
                break;
            }else {
                System.out.print("选择错误，请重新输入：");
            }
        }
        return c;
    }
    private static String readKeyBoard(int limit) {
        String line="";
        while (sc.hasNext()) {
            line = sc.nextLine();
            if(line.length()<1||line.length()>limit){
                //System.out.print("输入长度(不大于" + limit + ")错误，请重新输入v:");
                continue;
            }
            break;
        }
        return line;
    }
}