第十次作业

1、编写一个方法，实现冒泡排序（由小到大），并调用该方法

package apex;

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

public class apex {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int[] a = { 100, 88, 79, 98 };
        mp(a);
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }

    public static void mp(int[] b) {
        for (int i = 0; i < b.length - 1; i++) {
            for (int j = 0; j < b.length - 1 - i; j++) {
                if (b[j] > b[j + 1]) {
                    int temp = b[j];
                    b[j] = b[j + 1];
                    b[j + 1] = temp;
                }
            }
        }
    }
}

 

 2.编写一个方法，求整数n的阶乘，例如5的阶乘是1*2*3*4*5。 [必做题]

package apex;

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

public class apex {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int sum = jc(6);
        System.out.println(sum);
    }

    public static int jc(int a) {
        int sum = 1;
        for (int x = 1; x <= a; x++) {
            sum *= x;
        }
        return sum;
    }
}

 

 3.编写一个方法，判断该年份是平年还是闰年。[必做题]

package apex;

import java.util.Scanner;

public class apex {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        year();
    }
    public static void year() {
        Scanner  input= new Scanner(System.in);
        System.out.println("请输入年份");
        int year = input.nextInt();
        if (year % 4 == 0 && year % 10 != 0 || year % 400 == 0) {
            System.out.println("是闰年");
        } else {
            System.out.println("是平年");

        }
    }
}

 

 4.课堂没完成的menu菜单，实现幸运抽奖功能

package apex;

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

public class apex {
    private static Scanner input;
    private static Scanner input21;
    private static Scanner input3;
    private static Scanner input2;
    private static Scanner input4;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        mainMenu();
    }

    public static void mainMenu() {
        input2 = new Scanner(System.in);
        System.out.println("欢迎使用本系统");
        System.out.println("1.登录");
        System.out.println("2.注册");
        System.out.println("3.幸运抽奖");
        System.out.println("4.退出");
        System.out.println("请选择");
        int i = input2.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            reg();
            break;
        case 3:
            lucky();
        }
    }

    private static void lucky() {

        input21 = new Scanner(System.in);
        System.out.println("请输入四位会员卡号");
        Random r = new Random();
        int x = r.nextInt(100);
        int a = input21.nextInt();
        while (a < 1000 || a > 10000) {
            System.out.println("请重新输入");
            a = input21.nextInt();
            if (a < 1000 || a > 10000) {
                break;
            }
        }
        int bw = a % 1000 / 100;
        if (bw == x) {
            System.out.println("恭喜成为幸运会员");
        } else {
            System.out.println("很遗憾不是幸运会员");
        }
        returnMain();
    }

    public static void returnMain() {
        input = new Scanner(System.in);
        System.out.println("是否返回主菜单？");
        if (input.next().equalsIgnoreCase("Y"))
            mainMenu();
        else
            System.out.println("谢谢使用");
    }

    public static void reg() {
        input3 = new Scanner(System.in);
        System.out.println("输入要注册的用户名");
        String uname = input3.next();
        System.out.println("输入注册密码");
        String upwd = input3.next();
        System.out.println("注册成功");
        returnMain();
    }

    public static void login() {
        input4 = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = input4.next();
        System.out.println("输入密码");
        String upwd = input4.next();
        if (uname.equals("zs") && upwd.equals("123")) {
            System.out.println("ok");
        } else {
            System.out.println("fail");
        }
        returnMain();
    }
}