Java第十周作业
1.编写一个方法,实现冒泡排序(由小到大),并调用该方法。
package cn; public class Test1 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub int []x={1,3,2,5,8,7,9}; mp(x); for (int i = 0; i < x.length; i++) { System.out.println(x[i]); } } public static void mp(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 cn;
public class Test2 {
public static int jc(int x) {
int sum = 1;
for (int i = 1; i <= x; i++) {
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。[必做题]
package cn;
import java.util.Scanner;
public class Test3 {
public static void rp() {
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("是闰年");
} else {
System.out.println("是平年");
}
}
public static void main(String[] args) {
rp();
}
}
4.课堂没完成的menu菜单,实现幸运抽奖功能
package cn; import java.util.Random; import java.util.Scanner; public class Test4 { 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.退出系统"); System.out.println("请选择:"); int i = input.nextInt(); switch (i) { case 1: login(); break; case 2: register(); break; case 3: xycj(); break; } } public static void register() { 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 pwd = input.next(); System.out.println("注册成功"); 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 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 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 xycj() { Scanner input = new Scanner(System.in); System.out.println("输入一个4位会员卡号"); int number = input.nextInt(); int baiwei = number / 100 % 10; Random r = new Random(); int a = (int) r.nextInt(10); if (baiwei == a) { System.out.println("该用户是幸运会员"); } else { System.out.println("该用户不是幸运会员"); } returnMain(); } public static void main(String[] args) { mainMenu(); } }