5.7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 week10; public class PaiXu { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int x[] = { 1, 5, 6, 2, 3, 4 }; paiXu(x); for (int i = 0; i < x.length; i++) { System.out.println(x[i]); } } public static void paiXu(int a[]) { for (int i = 0; i < a.length - 1; i++) { for (int j = 0; j < a.length - 1 - i; j++) { if (a[j] > a[j + 1]) { int temp = a[j]; a[j] = a[j + 1]; a[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 week10; public class Jc { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int sum1=jc(5); System.out.println(sum1); } public static int jc(int n){ int sum=1; for (int i =1; i <=n; i++) { sum*=i; } 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 week10; import java.util.Scanner; public class Year { /** * @param args */ 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("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"); } } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package week10; import java.util.Random; import java.util.Scanner; public class Menu { 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(); } } public 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 Scanner input = new Scanner(System.in); System.out.println("输入一个四位数"); Random r = new Random(); int x = r.nextInt(10); int num = input.nextInt(); while (num < 1000 || num > 10000) { System.out.println("输入有误,重新输入"); num = input.nextInt(); if (num >= 1000 && num < 10000) { break; } } int bai = num % 1000 / 100; if (bai == x) { System.out.println("幸运会员"); } else { System.out.println("不是幸运会员"); } 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(); } }