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
package apex; import java.util.Random; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub int[] a = { 100, 88, 79, 98 }; mp(a); for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } public static void mp(int[] b) { for (int i = 0; i < b.length - 1; i++) { for (int j = 0; j < b.length - 1 - i; j++) { if (b[j] > b[j + 1]) { int temp = b[j]; b[j] = b[j + 1]; b[j + 1] = temp; } } } } }
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 apex; import java.util.Random; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub int sum = jc(6); System.out.println(sum); } public static int jc(int a) { int sum = 1; for (int x = 1; x <= a; x++) { sum *= x; } 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 apex; import java.util.Scanner; public class apex { public static void main(String[] args) { // TODO Auto-generated method stub year(); } 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 % 10 != 0 || year % 400 == 0) { System.out.println("是闰年"); } else { System.out.println("是平年"); } } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package apex; import java.util.Random; import java.util.Scanner; public class apex { private static Scanner input; private static Scanner input21; private static Scanner input3; private static Scanner input2; private static Scanner input4; public static void main(String[] args) { // TODO Auto-generated method stub mainMenu(); } public static void mainMenu() { input2 = 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 = input2.nextInt(); switch (i) { case 1: login(); break; case 2: reg(); break; case 3: lucky(); } } private static void lucky() { input21 = new Scanner(System.in); System.out.println("请输入四位会员卡号"); Random r = new Random(); int x = r.nextInt(100); int a = input21.nextInt(); while (a < 1000 || a > 10000) { System.out.println("请重新输入"); a = input21.nextInt(); if (a < 1000 || a > 10000) { break; } } int bw = a % 1000 / 100; if (bw == x) { System.out.println("恭喜成为幸运会员"); } else { System.out.println("很遗憾不是幸运会员"); } returnMain(); } public static void returnMain() { 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() { input3 = new Scanner(System.in); System.out.println("输入要注册的用户名"); String uname = input3.next(); System.out.println("输入注册密码"); String upwd = input3.next(); System.out.println("注册成功"); returnMain(); } public static void login() { input4 = new Scanner(System.in); System.out.println("输入用户名"); String uname = input4.next(); System.out.println("输入密码"); String upwd = input4.next(); if (uname.equals("zs") && upwd.equals("123")) { System.out.println("ok"); } else { System.out.println("fail"); } returnMain(); } }