第十周作业

1.编写一个方法，实现冒泡排序（由小到大），并调用该方法

import java.util.Scanner;


public class ooo {
    public static void maopao() {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入数组个数");
        int i=input.nextInt();
        int []a=new int[i];
        for(int c=0;c<i;c++)
        {
            System.out.println("请输入第"+(c+1)+"个数组");
            a[c] =input.nextInt();
        }
        int max = a[0];
        for (int z = 0; z < a.length; z++) {
            for (int j = z; j < a.length; j++) {
               if (a[j] < a[z]) {
                   max = a[z];
                   a[z] = a[j];
                   a[j] = max;
               }
            }
        }
    System.out.println("从小到大排序");
    for (int z:a) {
        System.out.println(z);}
    }

    public static void main(String[] args) {
        maopao();
    }
}

 

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]

 

 

import java.util.Scanner;


public class ooo {
    public static void jiecheng() {
        int sum = 1;
        System.out.println("请输入数字");
        Scanner input = new Scanner(System.in);
        int a = input.nextInt();
        for (int i = 1; i <= a; i++) {
            sum *= i;
        }
        System.out.println("该数的阶乘为" + sum);
    }

    public static void main(String[] args) {
        jiecheng();
    }

}

 

 

 3.编写一个方法，判断该年份是平年还是闰年。[必做题]

import java.util.Scanner;


public class ooo {
    public static void year() {
        System.out.println("请输入年份");
        Scanner input = new Scanner(System.in);
        int a = input.nextInt();
        if (a % 4 == 0 && a % 100 != 0 || a % 400 == 0) {
            System.out.println("该年份是闰年");
        } else {
            System.out.println("该年份不是闰年");
        }
    }

    public static void main(String[] args) {
        year();
    }
}

 

 4.课堂没完成的menu菜单，实现幸运抽奖功能

public static void mainMenu() {
        Scanner input = 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.退出系统");
        System.out.println("请选择：");
        int i = input.nextInt();
        switch (i) {
        case 1:
            login();
            break;
        case 2:
            register();
            break;
        case 3:
            choujiang();
            break;
        }
    }
 
    public static void register() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = input.next();
        System.out.println("输入密码");
        String pwd = input.next();
        System.out.println("注册成功");
        returnMain();
    }
 
    public static void returnMain() {
        Scanner input = new Scanner(System.in);
        System.out.println("是否返回主菜单？Y/N");
        if (input.next().equalsIgnoreCase("Y"))
            mainMenu();
        else
            System.out.println("谢谢使用");
    }
 
    public static void login() {
        Scanner input = new Scanner(System.in);
        System.out.println("输入用户名");
        String uname = input.next();
        System.out.println("输入密码");
        String pwd = input.next();
        if (uname.equals("1") && pwd.equals("1"))
            System.out.println("成功");
        else
            System.out.println("失败");
        returnMain();
 
    }
 
    public static void choujiang() {
        Scanner sc = new Scanner(System.in);
        Random r = new Random();
        int a = r.nextInt(10);
        System.out.println("输入四位会员卡号");
        int number = sc.nextInt();
        int b = number % 100 / 10;
        System.out.println("幸运数字为" + a);
        if (b == a) {
            System.out.println("是幸运会员");
        } else {
            System.out.println("不是幸运会员");
        }
        returnMain();
    }
 
    public static void main(String[] args) {
        mainMenu();
    }