Java第十周作业
上机练习
1.两个数求平方和
1 package Class; 2 3 public class Exe1 { 4 public static int pfh(int a, int b) { 5 int pfh = a * a + b * b; 6 return pfh; 7 } 8 9 public static void main(String[] args) { 10 System.out.println(pfh(1, 2)); 11 } 12 }
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
1 package Homework; 2 3 import java.util.Scanner; 4 5 public class Home1 { 6 public static void mppx() { 7 Scanner input = new Scanner(System.in); 8 System.out.println("请输入五个数"); 9 int s[] = new int[5]; 10 for (int i = 0; i < s.length; i++) { 11 s[i] = input.nextInt(); 12 } 13 for (int i = 0; i < s.length - 1; i++) { 14 for (int j = 0; j < s.length - 1 - i; j++) { 15 if (s[j] > s[j + 1]) { 16 int temp = s[j]; 17 s[j] = s[j + 1]; 18 s[j + 1] = temp; 19 } 20 } 21 } 22 System.out.println("排序后"); 23 for (int i = 0; i < s.length; i++) { 24 System.out.println(s[i]); 25 } 26 } 27 28 public static void main(String[] args) { 29 mppx(); 30 } 31 }
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]
1 package Homework; 2 3 public class Home2 { 4 public static int jc(int x) { 5 int sum = 1; 6 for (int i = 1; i <= x; i++) { 7 sum *= i; 8 } 9 return sum; 10 } 11 12 public static void main(String[] args) { 13 System.out.println(jc(5)); 14 } 15 }
3.编写一个方法,判断该年份是平年还是闰年。[必做题]
1 package Homework; 2 3 import java.util.Scanner; 4 5 public class Home3 { 6 public static void rnpn() { 7 Scanner input = new Scanner(System.in); 8 System.out.println("请输入年份"); 9 int year = input.nextInt(); 10 if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { 11 System.out.println("该年份是闰年"); 12 } else { 13 System.out.println("该年份是平年"); 14 } 15 } 16 17 public static void main(String[] args) { 18 rnpn(); 19 } 20 }
4.课堂没完成的menu菜单,实现幸运抽奖功能
1 package Homework; 2 3 import java.util.Random; 4 import java.util.Scanner; 5 6 public class Home4 { 7 public static void mainMenu() { 8 Scanner input = new Scanner(System.in); 9 System.out.println("欢迎使用本系统"); 10 System.out.println("1.登录"); 11 System.out.println("2.注册"); 12 System.out.println("3.幸运抽奖"); 13 System.out.println("4.退出"); 14 System.out.println("请选择:"); 15 int i = input.nextInt(); 16 switch (i) { 17 case 1: 18 login(); 19 break; 20 case 2: 21 register(); 22 break; 23 case 3: 24 draw(); 25 break; 26 } 27 } 28 29 public static void draw() { 30 Scanner input = new Scanner(System.in); 31 System.out.println("请输入四位会员卡号"); 32 int x = input.nextInt(); 33 int a = x / 100 % 10; 34 Random r = new Random(); 35 int b = r.nextInt(10); 36 if (a == b) { 37 System.out.println("该用户是幸运会员"); 38 } else { 39 System.out.println("该用户不是幸运会员"); 40 } 41 returnMain(); 42 } 43 44 public static void register() { 45 Scanner input = new Scanner(System.in); 46 System.out.println("输入用户名"); 47 String uname = input.next(); 48 System.out.println("输入密码"); 49 String pwd = input.next(); 50 System.out.println("注册成功"); 51 returnMain(); 52 53 } 54 55 public static void returnMain() { 56 Scanner input = new Scanner(System.in); 57 System.out.println("是否返回主菜单?Y/N"); 58 if (input.next().equalsIgnoreCase("Y")) 59 mainMenu(); 60 else 61 System.out.println("谢谢使用"); 62 } 63 64 public static void login() { 65 Scanner input = new Scanner(System.in); 66 System.out.println("输入用户名"); 67 String uname = input.next(); 68 System.out.println("输入密码"); 69 String pwd = input.next(); 70 if (uname.equals("admin") && pwd.equals("admin")) 71 System.out.println("成功"); 72 else 73 System.out.println("失败"); 74 returnMain(); 75 76 } 77 78 public static void main(String[] args) { 79 mainMenu(); 80 } 81 }