JAVA第十周作业0507

package com.homework10;

import java.util.Scanner;

//1.编写一个方法，实现冒泡排序（由小到大），并调用该方法
public class Exe10_1 {
    public static void Small(int a[]) {
        for (int i = 0; i < a.length; i++) {
            for (int j = i; j < a.length; j++) {
                if(a[i]>a[j]){
                    int temp = a[i];
                    a[i] = a[j];
                    a[j] = temp;
                }
            }
        }
    }
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int []a = new int [5];
        System.out.println("请输入5个整数！");
        for (int i = 0; i < a.length; i++) {
            a[i] = input.nextInt();
        }
        Small(a);
        /*for (int i : a) {
            System.out.println(i);
        }*/
        for (int i = 0; i < a.length; i++) {
            System.out.print(a[i] + "\t");
        }
    }
}

 

 

 

package com.homework10;

import java.util.Scanner;

//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]
public class Exe10_2 {
    public static int jc(int num) {
        int cj = 1;
        for (int i = 1; i <= num; i++) {
            cj *= i;
        }
        return cj;
    }
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入一个整数，求其阶乘！");
        int jc = jc(input.nextInt());
        System.out.print(jc);
    }
}

 

 

 

package com.homework10;

import java.util.Scanner;

//3.编写一个方法，判断该年份是平年还是闰年。[必做题]
public class Exe10_3 {
    public static void year(int year) {
        if (year%4==0 && year%100!=0||year%400==0) {
            System.out.print(year + "年是闰年!");
        } else {
            System.out.print(year + "年不是闰年!");
        }
    }
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入一个年份，判断是否闰年！");
        year(input.nextInt());
    }
}

 

 

 

package com.homework10;

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

public class Exe10_4 {
    Scanner input = new Scanner(System.in);
    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");
        System.out.println("请选择");
        int i=input.nextInt();
        switch(i){
        case 1:
            login();
            break;
        case 2:
            reg();
            break;
        case 3:
            lucky();
        }    
    }
    
    private static void lucky() {
        // 输入四位会员卡号，如果百位数等于随机数，幸运会员。否则不是。同时也要询问是否返回主菜单
        Random r = new Random();
        Scanner input = new Scanner(System.in);
        int luck = r.nextInt(10);
        System.out.println("请输入一个4位会员卡号:");
        int id = input.nextInt();
        if (id%10/10==luck) {
            System.out.println(id + " 您是幸运会员!");
        } else {
            System.out.print(id + " 您是普通会员!");
        }
            System.out.println("\tluck = "+luck);
            returnMain();
    }

    public static void returnMain(){
        Scanner 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() {
        // TODO Auto-generated method stub
        Scanner input=new Scanner(System.in);
        System.out.println("输入要注册的用户名");
        String uname=input.next();
        System.out.println("输入注册密码");
        String upwd=input.next();
        System.out.println("注册成功");
        returnMain();
    }

    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 upwd=input.next();
        if(uname.equals("zs")&&upwd.equals("123")){
            System.out.println("ok");
        }else{
            System.out.println("fail");
        }
        returnMain();        
    }
    
    public static void main(String[] args) {
        mainMenu();

    }
    
}