宿舍管理查询系统要求

Question

(1）主体要求：为宿舍管理人员编写一个宿舍管理软件，程序设计要求为：
A. 采用交互工作方式，功能菜单下可连续操作，直至选择退出
B.建立数据文件 ，数据文件按关键宇(姓名、学号、房号）进行排序(冒泡、选择、插入
排序等任诜一种）
(2）查询菜单：用二分查找实现以下查询功能：
A.按姓名查询
B.按学号杳询
C.按房号查询
（3）其它功能：插入、删除、修改学生信息，每个操作都需打印操作结果

Answer 1

首先，我们需要定义一个类来存储学生信息，包括姓名、学号、房号。

public class Student {
    private String name;
    private String studentId;
    private String dormitoryId;

    public Student(String name, String studentId, String dormitoryId) {
        this.name = name;
        this.studentId = studentId;
        this.dormitoryId = dormitoryId;
    }

    public String getName() {
        return name;
    }

    public String getStudentId() {
        return studentId;
    }

    public String getDormitoryId() {
        return dormitoryId;
    }
}

然后，我们可以创建一个类来管理宿舍信息，并实现插入、删除、修改学生信息的功能。

import java.util.ArrayList;
import java.util.List;

public class DormitoryManager {
    private List<Student> students;

    public DormitoryManager() {
        students = new ArrayList<>();
    }

    public void addStudent(Student student) {
        students.add(student);
    }

    public void deleteStudent(String studentId) {
        for (int i = 0; i < students.size(); i++) {
            if (students.get(i).getStudentId().equals(studentId)) {
                students.remove(i);
                return;
            }
        }
    }

    public void updateStudent(String studentId, Student newStudent) {
        for (int i = 0; i < students.size(); i++) {
            if (students.get(i).getStudentId().equals(studentId)) {
                students.set(i, newStudent);
                return;
            }
        }
    }
}

接下来，我们可以创建一个类来实现查询功能，包括按姓名、学号、房号查询。

在这里，我们使用二分查找来实现查询功能，时间复杂度为 $O(\log n)$，其中 $n$ 为学生总数。

import java.util.List;

public class QueryManager {
    public static int binarySearch(List<Student> students, String key, int l, int r, Getter getter) {
        while (l <= r) {
            int mid = l + (r - l) / 2;
            int cmp = getter.get(students.get(mid)).compareTo(key);
            if (cmp == 0) {
                return mid;
            } else if (cmp < 0) {
                l = mid + 1;
            } else {
                r = mid - 1;
            }
        }
        return -1;
    }

    public static Student searchByName(List<Student> students, String name) {
        int index = binarySearch(students, name, 0, students.size() - 1, new Getter() {
            @Override
            public String get(Student student) {
                return student.getName();
            }
        });
        return index == -1 ? null : students.get(index);
    }

    public static Student searchByStudentId(List<Student> students, String studentId) {
        int index = binarySearch(students, studentId, 0, students.size() - 1, new Getter() {
            @Override
            public String get(Student student) {
                return student.getStudentId();
            }
        });
        return index == -1 ? null : students.get(index);
    }

    public static Student searchByDormitoryId(List<Student> students, String dormitoryId) {
        int index = binarySearch(students, dormitoryId, 0, students.size() - 1, new Getter() {
            @Override
            public String get(Student student) {
                return student.getDormitoryId();
            }
        });
        return index == -1 ? null : students.get(index);
    }

    public interface Getter {
        String get(Student student);
    }
}

最后，我们可以创建一个类来实现交互工作方式，并通过菜单连续操作。

为了方便，我们可以使用 Scanner 类来读取用户的输入。

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        DormitoryManager dormitoryManager = new DormitoryManager();
        QueryManager queryManager = new QueryManager();

        while (true) {
            System.out.println("1. 查询");
            System.out.println("2. 插入");
            System.out.println("3. 删除");
            System.out.println("4. 修改");
            System.out.println("5. 退出");
            System.out.print("请输入你的选择：");

            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    System.out.println("1. 按姓名查询");
                    System.out.println("2. 按学号查询");
                    System.out.println("3. 按房号查询");
                    System.out.print("请输入你的选择：");
                    int queryChoice = scanner.nextInt();
                    switch (queryChoice) {
                        case 1:
                            System.out.print("请输入姓名：");
                            String name = scanner.next();
                            Student student = queryManager.searchByName(dormitoryManager.getStudents(), name);
                            if (student == null) {
                                System.out.println("未找到学生信息。");
                            } else {
                                System.out.println("学生信息如下：");
                                System.out.println("姓名：" + student.getName());
                                System.out.println("学号：" + student.getStudentId());
                                System.out.println("房号：" + student.getDormitoryId());
                            }
                            break;
                        case 2:
                            System.out.print("请输入学号：");
                            String studentId = scanner.next();
                            student = queryManager.searchByStudentId(dormitoryManager.getStudents(), studentId);
                            if (student == null) {
                                System.out.println("未找到学生信息。");
                            } else {
                                System.out.println("学生信息如下：");
                                System.out.println("姓名：" + student.getName());
                                System.out.println("学号：" + student.getStudentId());
                                System.out.println("房号：" + student.getDormitoryId());
                            }
                            break;
                        case 3:
                            System.out.print("请输入房号：");
                            String dormitoryId = scanner.next();
                            student = queryManager.searchByDormitoryId(dormitoryManager.getStudents(), dormitoryId);
                            if (student == null) {
                                System.out.println("未找到学生信息。");
                            } else {
                                System.out.println("学生信息如下：");
                                System.out.println("姓名：" + student.getName());
                                System.out.println("学号：" + student.getStudentId());
                                System.out.println("房号：" + student.getDormitoryId());
                            }
                            break;
                        default:
                            System.out.println("输入无效，请重新输入。");
                            break;
                    }
                    break;
                case 2:
                    System.out.println("请输入学生信息：");
                    System.out.print("姓名：");
                    String name = scanner.next();
                    System.out.print("学号：");
                    String studentId = scanner.next();
                    System.out.print("房号：");
                    String dormitoryId = scanner.next();
                    dormitoryManager.addStudent(new Student(name, studentId, dormitoryId));
                    System.out.println("插入成功。");
                    break;
                case 3:
                    System.out.print("请输入学号：");
                    studentId = scanner.next();
                    dormitoryManager.deleteStudent(studentId);
                    System.out.println("删除成功。");
                    break;
                case 4:
                    System.out.println("请输入学生信息：");
System.out.print("学号：");
                    studentId = scanner.next();
                    System.out.print("姓名：");
                    name = scanner.next();
                    System.out.print("房号：");
                    dormitoryId = scanner.next();
                    dormitoryManager.updateStudent(studentId, new Student(name, studentId, dormitoryId));
                    System.out.println("修改成功。");
                    break;
                case 5:
                    System.out.println("退出系统。");
                    return;
                default:
                    System.out.println("输入无效，请重新输入。");
                    break;
            }
        }
    }
}

这样，我们就完成了使用 Java 编写的宿舍管理查询系统。