第十周上机课作业\

1.编写一个方法，实现冒泡排序（由小到大），并调用该方法

package gkd;

import java.util.Scanner;

public class test1 {
    public static void mppx() {
         Scanner input=new Scanner(System.in);
         System.out.println("请输入10个数");
         int []a=new int[10];
         for (int i = 0; i < a.length; i++) {
             a[i]=input.nextInt();
         }
         for (int i = 0; i < a.length-1; i++) {
             for (int j = 0; j < a.length-i-1; j++) {
                 if(a[j]>a[j+1]){
                 int temp=a[j];
                 a[j]=a[j+1];
                 a[j+1]=temp;
             }
             }
         }
         System.out.println("冒泡排序后");
         for (int i = 0; i < a.length; i++) {
             System.out.println(a[i]);
         }
     }
     public static void main(String[] args) {
         mppx();

     }

 
    }

 

 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 gkd;

import java.util.Scanner;
public class Demo {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("请输入一个数: ");
int n = sc.nextInt();
jiecheng(n);
}
public static int jiecheng(int n) {
int sum = 1;
for (int i = 1; i <= n; i++) {
sum *= i;
}
System.out.println("factorial(" + n + ")=" + sum);
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 gkd;

import java.util.Scanner;
public class Demo {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("请输入一个年份：");
int year=input.nextInt();
if ((year%4==0&&year%100!=0||year%400==0)) {
System.out.println("此年份为闰年");
}
else{
System.out.println("此年份不是闰年");
}
 }

}

 

 

4.课堂没完成的menu菜单，实现幸运抽奖功能

 

package gkd;
import java.util.Scanner;
import java.util.Random;
public class Demo {
     public static void mainMenu() {
            // TODO Auto-generated method stub
                    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() {
                    Scanner input=new Scanner(System.in);
                    Random r=new Random();
                    int x=r.nextInt(10);
                    System.out.println("幸运数字为"+x);
                    System.out.println("请输入四位幸运卡号");
                    int number=input.nextInt();
                    if (number/100%10==x) {
                        System.out.println("该卡号为幸运卡号");
                    }else{
                        System.out.println("该卡不是幸运卡号");
                    }
                    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("yes"))
                        mainMenu();
                        else
                            System.out.println("输入错误");
     
     
                }
                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("xsy")&&upwd.equals("666")) {
                        System.out.println("登陆成功");
                    }
                        else{
                            System.out.println("输入错误");
                        }
                    returnMain();
                    }
     
                public static void reg() {
                    Scanner input=new Scanner(System.in);
                    System.out.println("请输入要注册的用户名");
                    String uname=input.next();
                    System.out.println("请输入注册密码");
                    String upwd=input.next();
                    System.out.println("注册成功");
                    returnMain();
                }
     
     
     
                public static void main(String[] args) {
                    // TODO Auto-generated method stub
                    mainMenu();
     
                }
        }