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
import java.util.Scanner; public class Test2 { public static void PX() { System.out.println("请输入4个数字"); Scanner input = new Scanner(System.in); int a[] = new int[4]; 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 - 1; j++) { if (a[j] > a[j + 1]) { int temp = a[j]; a[j] = a[j + 1]; a[j + 1] = temp; } } } for (int i : a) { System.out.println(i); } } public static void main(String[] args) { PX(); } }
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。
package homework10; public class jc { public static int jc(int n){ int sum=1; for (int i = 1; i <= n; i++) { sum=sum*i; } return sum; } public static void main(String[] args){ System.out.println(jc(5)); } }
3.编写一个方法,判断该年份是平年还是闰年
import java.util.Scanner; public class Test2 { 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 % 100 != 0 || year % 400 == 0) System.out.println(year + "是闰年"); else System.out.println(year + "是平年"); } 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
import java.util.Random; import java.util.Scanner; public class Test2{ /** * @param args */ // 课堂没完成的menu菜单,实现幸运抽奖功能 public static void mainmenu() { // 建立主菜单 Scanner input = new Scanner(System.in); System.out.println("欢迎登录本系统"); 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: raffle(); break; } } public static void login() { // 1.登录 Scanner input = new Scanner(System.in); System.out.println("输入用户名"); String uname = input.next(); System.out.println("请输入密码"); String pwd = input.next(); if (uname.equals("admin") && pwd.equals("admin")) System.out.println("成功"); else System.out.println("失败"); returnMain(); } public static void register() { // 2.注册 Scanner input = new Scanner(System.in); System.out.println("输入用户名"); String uname = input.next(); System.out.println("请输入密码"); String pwd = input.next(); System.out.println("注册成功"); returnMain(); } public static void raffle() { // 3.抽奖 Random r = new Random(); int yu = r.nextInt(10); Scanner input = new Scanner(System.in); System.out.println("请输入四位会员号"); int num = input.nextInt(); int bai = num / 10 % 100; if (bai == yu) { System.out.println("是会员号"); } else System.out.println("不是会员号"); 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 main(String[] args) { mainmenu(); } }