package Dmh; import java.util.Random; import java.util.Scanner; public class zy425 { public static void main(String[] args) { MainMenu(); } public static void MainMenu() { Scanner input = new Scanner(System.in); System.out.println("1.登录"); System.out.println("2.注册"); System.out.println("3.幸运抽奖"); System.out.println("4.看小故事"); System.out.println("5.退出"); System.out.println("请选择"); int i = input.nextInt(); switch (i) { case 1: login(); break; case 2: zhuce(); break; case 3: choujiang(); break; case 4: story(); break; case 5: tc(); break; } } public static void tc() { System.out.println("谢谢使用"); } public static void story() { Scanner input = new Scanner(System.in); System.out.println("请选择想看的故事:"); System.out.println("1.卖火柴的小女孩"); System.out.println("2.小红帽"); int m = input.nextInt(); switch (m) { case 1: System.out.println("卖火柴的小女孩"); break; case 2: System.out.println("小红帽"); break; } returnMain(); } private static void choujiang() { Scanner input = new Scanner(System.in); System.out.println("请输入四位会员卡号"); int x = input.nextInt(); Random r = new Random(); int n = r.nextInt(10); if (x / 100 % 10 == n) { System.out.println("恭喜你中奖啦"); } else { System.out.println("谢谢参与"); } returnMain(); } private static void zhuce() { Scanner input = new Scanner(System.in); System.out.println("请输入用户名"); String name = input.next(); System.out.println("请输入密码"); String mima = input.next(); System.out.println("请再次输入密码"); String mima = input.next(); System.out.println("注册成功"); returnMain(); } private static void login() { Scanner input = new Scanner(System.in); System.out.println("请输入用户名"); String uname = input.next(); System.out.println("请输入密码"); String upwd = input.next(); if (uname.equals("nnn") && upwd.equals("568")) { System.out.println("登录成功"); } else { System.out.println("登录失败"); } returnMain(); } public static void returnMain() { System.out.println("是否返回主菜单?Y/N"); Scanner input = new Scanner(System.in); if (input.next().equalsIgnoreCase("Y")) { MainMenu(); } else { System.out.println("谢谢使用"); } } }
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 Dmh; import java.util.Scanner; public class zy458 { private static int jc(int x) { int sum = 1; for (int i = x; i > 0; i--) { sum *= i; } return sum; } public static void main(String[] args) { Scanner input= new Scanner(System.in); System.out.println("请输入数字:"); int i=input.nextInt(); System.out.println("阶乘等于:"+jc(i)); } } 3.编写一个方法,判断该年份是平年还是闰年 package Dmh; import java.util.Scanner; public class zy425 { private static boolean run(int year) { return year % 4 == 0 && year % 100 != 0 || year % 400 == 0; } public static void main(String[] args) { System.out.println("请输入一个年份"); Scanner s = new Scanner(System.in); if (run(s.nextInt())) { System.out.println("是闰年"); } else { System.out.println("不是闰年"); } } }