java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 shi; public class test1 { public static void maopao(int x[] ) { int a = 0; for (int i = x.length - 1; i > 0; i--) { for (int j = 0; j < i; j++) { if (x[j] > x[i]) { a = x[j]; x[j] = x[i]; x[i] = a; } } } } public static void main(String[] args) { int x[] = { 9, 5, 7, 2, 3, 1, 5 }; maopao(x); for (int i : x) { System.out.print(i + "\t"); } } }
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 shi; import java.util.Scanner; public class test1 { public static int jc (int a ) { int sum=1; for (int i = 1; i <= a; i++) { sum*=i; } return sum; } public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("输入一个数"); int jc = jc(input.nextInt()); System.out.print("阶乘是"+jc); } }
3.编写一个方法,判断该年份是平年还是闰年。[必做题]
package shi; import java.util.Scanner; public class test2 { public static int judge () { 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("该年份为闰年!");} else{ System.out.println("该年份为平年!");} return year; } public static void main(String[] args) { judge(); } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package shi; import java.util.Random; import java.util.Scanner; public class test { public static void mainMenu() { Scanner input = new Scanner(System.in); System.out.println("欢迎使用本系统Random"); 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() { // 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 Random r = new Random(); Scanner input = new Scanner(System.in); int luck = r.nextInt(10); System.out.println("输入一个4位数会员卡号"); int id= input.nextInt(); if (id%10/10 == luck) { System.out.println(id+"是幸运会员" ); } else { System.out.println(id+"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(); } }