JAVA1 类型转换

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);double d = scanner.nextDouble();System.out.println(Main.typeConversion(d));}public static int typeConversion(double d){//write your code here......return (int)d;}
}

JAVA2 简单运算

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int a = scanner.nextInt();int b = scanner.nextInt();scanner.close();//write your code here......int sum = a + b;int difference = a > b ? a - b : b - a;int product = a * b;int quotient = a > b ? a / b : b / a;int module = a > b ? a % b : b % a;System.out.println(sum + " " + difference + " " + product + " " + quotient + " " + module);}
}

JAVA3 四舍五入

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);double d= scanner.nextDouble();//write your code here......int i = (int)(d * 10) % 10 >= 5 ? (int)d + 1 : (int)d;System.out.println(i);}
}

JAVA4 交换变量值

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int a = scanner.nextInt();int b = scanner.nextInt();//write your code here.......int temp = a;a = b;b = temp;System.out.println(a+" "+b);}
}

JAVA5 计算商场折扣

import java.util.*;public class Main {public static void main(String[] args) {Scanner console = new Scanner(System.in);int price = console.nextInt();int cost = 0;//write your code here......if (price < 100) {cost = price;} else if (price < 500) {cost = (int)(price * 0.9);} else if (price < 2000) {cost = (int)(price * 0.8);} else if (price < 5000) {cost = (int)(price * 0.7);} else {cost = (int)(price * 0.6);}System.out.println(cost);}
}

JAVA6 判断体重指数

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);double height = scanner.nextDouble();double weight = scanner.nextDouble();//write your code here......double bmi = weight / (height * height);if (bmi < 18.5) {System.out.println("偏瘦");} else if (bmi < 20.9) {System.out.println("苗条");} else if (bmi < 24.9) {System.out.println("适中");} else {System.out.println("偏胖");}}
}

JAVA7 判断学生成绩等级

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String grade =scanner.next();//write your code here......switch (grade) {case "A":System.out.println("优秀");break;case "B":System.out.println("良好");break;case "C":System.out.println("及格");break;case "D":System.out.println("不及格");break;default:System.out.println("未知等级");}}
}

JAVA8 邮箱验证

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String str = scanner.next();String emailMatcher="[a-zA-Z0-9]+@[a-zA-Z0-9]+\\.[a-zA-Z0-9]+";//write your code here......if (str.matches(emailMatcher)) {System.out.println("邮箱格式合法");} else {System.out.println("邮箱格式不合法");}}
}

JAVA9 数列求和

public class Main {public static void main(String[] args) {//write your code here........long sum = 0;for (long i = 9; i <= 9999999999L; i = i * 10 + 9) {sum += i;}System.out.println(sum);}
}

JAVA10 统计输入正数个数

import java.util.*;public class Main {public static void main(String[] args) {int count = 0;Scanner scanner = new Scanner(System.in);//write your code here......while (scanner.nextInt() > 0) {count++;}System.out.println(count);}
}

JAVA11 求最小公倍数

import java.util.*;public class Main {public static void main(String[] args) {Scanner console = new Scanner(System.in);int m = console.nextInt();int n = console.nextInt();int result = getCM(m, n);System.out.println(result);}public static int getCM(int m, int n){//write your code here......int a = m > n ? m : n;int b = m > n ? n : m;while (b > 0) {int temp = a % b;a = b;b = temp;}return m * n / a;}
}

JAVA12 小球走过路程计算

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner=new Scanner(System.in);float h=scanner.nextFloat();int n =scanner.nextInt();//write your code here......float sum = h;h /= 2;for (int i = 1; i < n; ++i) {sum += h * 2;h /= 2;}System.out.println(String.format("%.3f", h)+" "+String.format("%.3f", sum));//输出格式为：System.out.println(String.format("%.3f", h)+" "+String.format("%.3f", sum));}
}

JAVA13 求平均数

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scan = new Scanner(System.in);//write your code here......int number;double avg = 0;int count = 0;while ((number = scan.nextInt()) != -1) {avg += number;count++;}avg /= count;//输出格式为：System.out.println(String.format("%.2f",avg));System.out.println(String.format("%.2f",avg));}
}

JAVA14 判断质数

import java.util.Scanner;public class Main {public static void main(String[] args) {Main main = new Main();Scanner scan = new Scanner(System.in);int number = scan.nextInt();System.out.println(main.isPrimeNumber(number));}public Boolean isPrimeNumber(int number) {//write your code here......for (int i = 2; i * i <= number; i++) {if (number % i == 0) {return false;}}return true;}
}

JAVA15 计算整数位数

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scan = new Scanner(System.in);int num = scan.nextInt();scan.close();//write code here......if (num > 0) {int numOfDigits = 0;while (num > 0) {numOfDigits++;num /= 10;}System.out.println(numOfDigits);} else {System.out.println(num);}}
}

JAVA16 数组遍历

import java.util.Scanner;public class Main {public static void main(String[] args) {int[] ary = new int[6];int max;int min;Scanner scanner = new Scanner(System.in);for (int i = 0; i  ary[i] ? ary[i] : min;}System.out.println(max+" "+min);}
}

JAVA17 数组倒转

import java.util.Arrays;
import java.util.Scanner;public class Main {public static void main(String[] args) {int[] arr = new int[6];Scanner scanner = new Scanner(System.in);for (int i = 0; i < arr.length; i++) {arr[i] = scanner.nextInt();}System.out.println(Arrays.toString(arr));//write your code here......for (int i = 0, j = arr.length - 1; i < j; i++, j--) {int temp = arr[i];arr[i] = arr[j];arr[j] = temp;}System.out.println(Arrays.toString(arr));}
}

JAVA18 二维数组求和

public class Main {public static void main(String[] args) {int[][]  arr = {{11,33,55},{22,44,66,88},{131,214,315,146},{928,827,726,625},{424,525}};int sum=add(arr);System.out.println(sum);}public static int add(int[][] arr) {int sum=0;//write your code here......for (int i = 0; i < arr.length; i++) {for (int j = 0; j < arr[i].length; j++) {sum += arr[i][j];}}return sum;}
}

JAVA19 修改Data类的定义

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();Data data = new Data(x, y);System.out.println(data.getX() + data.getY());}}}class Data {private int x;private int y;Data(int x, int y) {this.x = x;this.y = y;}public int getX() {return x;}public int getY() {return y;}}

JAVA20 验证年龄

import java.util.Scanner;public class Main {public static void main(String[] args) {Person p = new Person();Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int age = scanner.nextInt();p.setAge(age);System.out.println(p.getAge());}}}class Person {private int age;//write your code here......public void setAge(int age) {this.age = age;}public int getAge() {if (age < 0) {return 0;} else if (age > 200) {return 200;} else {return age;}}}

JAVA21 补全构造方法

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();int z = scanner.nextInt();Sub sub = new Sub(x, y, z);System.out.println(sub.calculate());}}}class Base {private int x;private int y;public Base(int x, int y) {this.x = x;this.y = y;}public int getX() {return x;}public int getY() {return y;}}class Sub extends Base {private int z;public Sub(int x, int y, int z) {//write your code heresuper(x, y);this.z = z;}public int getZ() {return z;}public int calculate() {return super.getX() * super.getY() * this.getZ();}}

JAVA22 重写计算逻辑

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();Sub sub = new Sub(x, y);sub.calculate();}}}class Base {private int x;private int y;public Base(int x, int y) {this.x = x;this.y = y;}public int getX() {return x;}public int getY() {return y;}public void calculate() {System.out.println(getX() * getY());}}class Sub extends Base {//write your code here......public Sub(int x, int y) {super(x, y);}public void calculate() {System.out.println(getY() == 0 ? "Error" : getX() / getY());}}

JAVA23 定义打印方法

import java.util.Scanner;public class Main {public static void main(String[] args) throws Exception {Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {String className = scanner.next();// print就是需要你定义的方法print(Class.forName(className).newInstance());}}//write your code here......private static void print(Object clazz) {System.out.println(clazz.toString());}}class First {public String toString() {return "First";}
}class Second {public String toString() {return "Second";}
}class Third {public String toString() {return "Third";}
}

JAVA24 类型判断

import java.util.Scanner;public class Main {public static void main(String[] args) throws Exception {Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {String className = scanner.next();Base obj = (Base) Class.forName(className).newInstance();System.out.println(getClassName(obj));}}public static String getClassName(Base obj) {//write your code here......return obj.getClass().getName();}}class Base {}class Sub1 extends Base {}class Sub2 extends Base {}

JAVA25 实现抽象方法

import java.util.Scanner;public class Main {public static void main(String[] args) {// Sub是需要你定义的子类Base base = new Sub();Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();base.setX(x);base.setY(y);System.out.println(base.calculate());}}}abstract class Base {private int x;private int y;public int getX() {return x;}public void setX(int x) {this.x = x;}public int getY() {return y;}public void setY(int y) {this.y = y;}public int calculate() {if (avg() == 0) {return 0;} else {return sum() / avg();}}/*** 返回x和y的和*/public abstract int sum();/*** 返回x和y的平均值*/public abstract int avg();}class Sub extends Base {//write your code here......public int sum() {return getX() + getY();}public int avg() {return (getX() + getY()) / 2;}}

JAVA26 实现接口

import java.util.Scanner;public class Main {public static void main(String[] args) {Comparator comparator = new ComparatorImpl();Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();System.out.println(comparator.max(x, y));}}}interface Comparator {/*** 返回两个整数中的最大值*/int max(int x, int y);
}//write your code here......
class ComparatorImpl implements Comparator {public int max(int x, int y) {return x > y ? x : y;}
}

JAVA27 重写父类方法

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int x = scanner.nextInt();int y = scanner.nextInt();Sub sub = new Sub(x, y);System.out.println(sub.sum());}}}class Base {private int x;private int y;public Base(int x, int y) {this.x = x;this.y = y;}public int getX() {return x;}public final int getY() {return y;}public final int sum() {return getX() + getY();}}class Sub extends Base {public Sub(int x, int y) {super(x, y);}//write your code here......public int getX() {return 10 * super.getX();}
}

JAVA28 创建单例对象

public class Main {public static void main(String[] args) {Singleton s1 = Singleton.getInstance();Singleton s2 = Singleton.getInstance();System.out.println(s1 == s2);}}class Singleton {private static Singleton instance;private Singleton() {}//write your code here......public static Singleton getInstance() {return instance;}}

JAVA29 动态字符串

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String str = scanner.next();//write your code here......StringBuilder modifiedStr = new StringBuilder();int ptr = str.length();modifiedStr.append(str, Math.max(ptr - 3, 0), ptr);ptr -= 3;while (ptr > 0) {modifiedStr.insert(0, str.substring(Math.max(ptr - 3, 0), ptr) + ",");ptr -= 3;}System.out.println(modifiedStr.toString());}
}

JAVA30 统计字符串中字母出现次数

import java.util.Scanner;public class Main {public static void main(String[] args) {String string = "H e l l o ! n o w c o d e r";Scanner scanner= new Scanner(System.in);String word = scanner.next();scanner.close();System.out.println(check(string, word));}public static int check(String str, String word) {//write your code here......char query = word.charAt(0);int count = 0;for (int i = 0; i < str.length(); i++) {if (str.charAt(i) == query) {count++;}}return count;}
}

JAVA31 十进制数转二进制数

import java.util.*;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int num = scanner.nextInt();//write your code here......System.out.println(Integer.toBinaryString(num));}
}

JAVA33 掷骰子游戏

import java.util.Random;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextInt()) {int seed = scanner.nextInt();Random random = new Random(seed);//write your code here......System.out.println(random.nextInt(6) + 1);}}}

JAVA34 求绝对值，平方根，对数，正弦值

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner=new Scanner(System.in);double num = scanner.nextDouble();//write your code here......System.out.println(Math.abs(num));System.out.println(Math.sqrt(num));System.out.println(Math.log(num));System.out.println(Math.sin(num));}
}

JAVA35 输出某一年的各个月份的天数

import java.util.Calendar;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner console = new Scanner(System.in);int year = console.nextInt();//write your code here......Calendar c = Calendar.getInstance();for (int month = 1; month <= 12; month++) {c.set(year, month - 1, 1);System.out.println(year + "年" + month + "月:" + c.getActualMaximum(Calendar.DAY_OF_MONTH) + "天");}}
}

JAVA36 日期换算

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;public class Main {public static void main(String[] args) throws ParseException {SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");Scanner in = new Scanner(System.in);String str1 = in.nextLine();//write your code here......try {Date date = new SimpleDateFormat("yyyy MM dd HH mm ss").parse(str1);System.out.println("北京时间为：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date));System.out.println("纽约时间为：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(date.getTime() - 12 * 60 * 60 * 1000));} catch (ParseException ex) {System.out.println("您输入的数据不合理");}}
}

JAVA37 判断学生成绩

import java.util.*;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int score = scanner.nextInt();//write your code here......try {if (0 <= score && score <= 100) {System.out.println(score);} else {throw new ScoreException("分数不合法");}} catch (ScoreException ex) {System.out.println(ex.getMessage());}}
}class ScoreException extends Exception {//write your code here......public ScoreException() {super();}public ScoreException(String message) {super(message);}}

JAVA38 字符串去重

import java.util.HashSet;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String str = scanner.nextLine();scanner.close();HashSet hs = new HashSet<>();//write your code here......for (int i = 0; i < str.length(); i++) {hs.add(str.charAt(i));}for (char c:hs) {System.out.print(c);}}
}

JAVA39 集合遍历

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);List list = new ArrayList<>();int num1 = scanner.nextInt();int num2 = scanner.nextInt();int num3 = scanner.nextInt();int num4 = scanner.nextInt();int num5 = scanner.nextInt();scanner.close();list.add(num1);list.add(num2);list.add(num3);list.add(num4);list.add(num5);System.out.print("普通for循环:");//write your code here......for (int i = 0; i < list.size(); i++) {System.out.print(list.get(i) + " ");}System.out.println();System.out.print("增强for循环:");//write your code here......for (Integer x : list) {System.out.print(x + " ");}System.out.println();System.out.print("迭代器遍历:");//write your code here......Iterator iter = list.listIterator();while (iter.hasNext()) {System.out.print(iter.next() + " ");}System.out.println();}
}

JAVA40 排队系统

import java.util.*;public class Main {public static void main(String[] args) {Guest guest1 = new Guest("小明",false);Guest guest2 = new Guest("小军",false);Guest vipGuest = new Guest("小红",true);Deque deque = new ArrayDeque<>();deque.add(guest1);deque.add(guest2);//write your code here......deque.push(vipGuest);System.out.println(deque);}
}
class Guest{String name;Boolean vip;@Overridepublic String toString() {return name;}public Guest(String name, Boolean vip) {this.name = name;this.vip = vip;}
}

JAVA41 Head and Tail of the Queue

import java.util.ArrayDeque;
import java.util.Scanner;public class Main {public static void main(String[] args) {ArrayDeque deque = new ArrayDeque();Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {String name = scanner.next();// 初始化队列中的数据deque.offerLast(name);}// write your code here......boolean fromFirst = true;while (!deque.isEmpty()) {if (fromFirst) {System.out.println(deque.pollFirst());} else {System.out.println(deque.pollLast());}fromFirst = !fromFirst;}}}

JAVA42 统计一句话中重复单词的个数

import java.util.*;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String line = scanner.nextLine();Map map = new LinkedHashMap();//write your code here......for (int i = 0; i < line.length(); i++) {char ch = line.charAt(i);if (('A' <= ch && ch <= 'Z') || ('a' <= ch && ch <= 'z')) {map.put(ch, map.getOrDefault(ch, 0) + 1);}}Set> entrys = map.entrySet();for (Map.Entry entry : entrys) {System.out.println(entry.getKey() + ":" + entry.getValue());}}
}

JAVA43 map简单应用

import java.util.*;public class Main {public static void main(String[] args) {Scanner scanner  = new Scanner(System.in);String name = scanner.next();Map map = new HashMap();map.put(1, "Amy");map.put(2, "Joe");map.put(3, "Tom");map.put(4, "Susan");//write your code here......for (Integer key : map.keySet()) {System.out.println(key + ":" + map.get(key));}map.put(5, name);map.remove(4);map.replace(3, "Tommy");System.out.println();for (Integer key : map.keySet()) {System.out.println(key + ":" + map.get(key));}}
}

JAVA44 集合排序

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);Customer customer1 = new Customer("小明",scanner.nextInt());Customer customer2 = new Customer("小军",scanner.nextInt());Customer customer3 = new Customer("小红",scanner.nextInt());List customers = new ArrayList<>();customers.add(customer1);customers.add(customer2);customers.add(customer3);//write your code here......Collections.sort(customers);System.out.println(customers);}
}class Customer implements Comparable{private String name;private int consumption;public Customer(String name, int consumption) {this.name = name;this.consumption = consumption;}@Overridepublic String toString() {return "Customer{" +"name='" + name + '\'' +", consumption=" + consumption +'}';}//write your code here......public int getConsumption() {return consumption;}public int compareTo(Customer customer) {return customer.getConsumption() - this.consumption;}}

JAVA45 判断各类型字符个数

import java.util.Scanner;public class Main {public static void main(String[] args) {int numbers = 0;int words = 0;int space = 0;int other = 0;Scanner scanner = new Scanner(System.in);String str = scanner.nextLine();//write your code here......for (int i = 0; i < str.length(); i++) {char ch = str.charAt(i);if (('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z')) {words++;} else if ('0' <= ch && ch <= '9') {numbers++;} else if (ch == ' ') {space++;} else {other++;}}System.out.println("英文字母"+words+"数字"+numbers+"空格"+space+"其他"+other);}
}

JAVA46 编写个人所得税计算程序

import java.util.*;public class Main {public static void main(String[] args) {List employees = new ArrayList<>();//write your code here......employees.add(new Employee("小明", 2500));employees.add(new Employee("小军", 8000));employees.add(new Employee("小红", 100000));for (Employee employee : employees) {double salaryForTax = employee.getSalary() - 3500;double tax = 0;if (salaryForTax <= 0) {tax = 0;} else if (salaryForTax <= 1500) {tax = salaryForTax * 0.03;} else if (salaryForTax <= 4500) {tax = salaryForTax * 0.10 - 105;} else if (salaryForTax <= 9000) {tax = salaryForTax * 0.20 - 555;} else if (salaryForTax <= 35000) {tax = salaryForTax * 0.25 - 1005;} else if (salaryForTax <= 55000) {tax = salaryForTax * 0.30 - 2755;} else if (salaryForTax <= 80000) {tax = salaryForTax * 0.35 - 5505;} else {tax = salaryForTax * 0.45 - 13505;}System.out.println(employee.getName() + "应该缴纳的个人所得税是：" + String.format("%.1f", tax));}}
}
class Employee{private String name;private double salary;public Employee(String name, double salary) {this.name = name;this.salary = salary;}public String getName() {return name;}public double getSalary() {return salary;}
}

JAVA47 记录点赞用户

import java.util.*;public class Main {public static void main(String[] args) {LikeRecorder recorder = new LikeRecorderImpl();Scanner scanner = new Scanner(System.in);while (scanner.hasNext()) {String name = scanner.next();recorder.like(name);}System.out.println(Arrays.toString(recorder.getLikeUsers()));}}/*** 点赞记录器*/
interface LikeRecorder {/*** 若用户没有点赞过，则记录此次点赞行为。* 若用户曾经点赞过，则删除用户点赞记录。** @param username 用户名*/void like(String username);/*** 返回所有点赞的用户名** @return 用户名数组*/String[] getLikeUsers();}class LikeRecorderImpl implements LikeRecorder {// write your code here......private HashSet users = new HashSet<>();public void like(String username) {if (users.contains(username)) {users.remove(username);} else {users.add(username);}}public String[] getLikeUsers() {return users.toArray(new String[users.size()]);}}

JAVA48 回文数判断

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner console = new Scanner(System.in);Main main = new Main();int number = console.nextInt();System.out.println(main.palindromeNumber(number));}public Boolean palindromeNumber(int number) {//write your code here......StringBuffer numStr = new StringBuffer("" + number);return numStr.toString().equals(numStr.reverse().toString());}
}

JAVA49 判断素数个数

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int start = scanner.nextInt();int end = scanner.nextInt();method(start,end);}public static void method(int start, int end) {int count=0;//write your code here......if (start > end) {int temp = start;start = end;end = temp;}for (int i = start <= 2 ? 3 : start; i <= end; ++i) {boolean isPrime = true;for (int j = 2; j * j <= i; j++) {if (i % j == 0) {isPrime = false;break;}}count += isPrime ? 1 : 0;}System.out.println(start+"到"+end+"之间有"+count+"个大于2的素数");}
}

JAVA50 根据周长求面积

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);while (scanner.hasNextDouble()) {double s = scanner.nextDouble();// Circle和Square是需要你定义的类System.out.println(String.format("%.3f",new Circle(s).getArea()));System.out.println(String.format("%.3f", new Square(s).getArea()));}}}class Shape {private double s; // 周长public Shape(double s) {this.s = s;}public double getS() {return s;}}interface Area {double getArea(); // 面积
}// 圆形
class Circle extends Shape implements Area {//write your code here......public Circle(double s) {super(s);}public double getArea() {return getS() * getS() / (4 * Math.PI);}}// 方形
class Square extends Shape implements Area {//write your code here......public Square(double s) {super(s);}public double getArea() {return getS() * getS() / 16;}}

JAVA51 冒泡排序

import java.util.Arrays;
import java.util.Scanner;
public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int[] arr = new int[7];for (int i = 0; i < arr.length; i++) {arr[i] = scanner.nextInt();}scanner.close();//write your code here......for (int j = arr.length - 1; j > 0; j--) {for (int i = j - 1; i >= 0; i--) {if (arr[i] > arr[j]) {int temp = arr[i];arr[i] = arr[j];arr[j] = temp;}}}for (int k = 0; k < arr.length; k++) {System.out.print(arr[k]+" ");}}
}