第十周作业
练:两个数求平方和的方法
package Test6; public class hw { public static int pfh(int a, int b) { return a * a + b * b; } public static void main(String[] args) { System.out.println(pfh(3, 4)); } }
1.编写一个方法,实现冒泡排序(由小到大),并调用该方法
package Test6; import java.util.Scanner; //1.编写一个方法,实现冒泡排序(由小到大),并调用该方法 public class h1 { public static void mppx() { Scanner input = new Scanner(System.in); int a[] = new int[3]; System.out.println("请输入3个数:"); for (int i = 0; i < a.length; i++) { a[i] = input.nextInt(); } 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; } } } System.out.println("排序后为:"); for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } } public static void main(String[] args) { mppx(); } }
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。
package Test6; //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。 public class h2 { public static int jc(int n) { int sum = 1; for (int i = 1; i <= n; i++) { sum *= i; } System.out.println("阶乘为:"); 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。
package Test6; import java.util.Scanner; //3.编写一个方法,判断该年份是平年还是闰年。 public class h3 { public static void panduan() { 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!"); } } public static void main(String[] args) { panduan(); } }
4.课堂没完成的menu菜单,实现幸运抽奖功能
package Test6; import java.util.Scanner; //4.课堂没完成的menu菜单,实现幸运抽奖功能 public class h4 { 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(); } } 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 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 xycj() { Scanner input = new Scanner(System.in); System.out.println("请输入四位数卡号:"); int kahao = input.nextInt(); int random = (int) (Math.random() * 10); if (random == kahao / 100 % 10) { System.out.println("恭喜你是幸运会员!"); } else { System.out.println("幸运数是:" + random); System.out.println("很遗憾你不是幸运会员!"); } returnMain(); } public static void main(String[] args) { mainMenu(); } }