用c++实现宿舍管理系统 要求： （1）能根据学生的学号找到学生的宿舍号 （2）能为宿舍添加学生，达到人数（比如 6 人）之后，提示该宿舍已满。提供空宿 舍编号。 （3）能够提供换宿舍服务。 （4）能够查找某个班级的学生在哪些宿舍 （5）字段信息可包括：学号，姓名，专业，班级，宿舍号等。

好的，以下是一个用C++实现宿舍管理系统的示例代码，其中实现了题目要求的各项功能：

#include <iostream>
#include <string>
#include <vector>
#include <map>

using namespace std;

// 学生类
class Student {
public:
    Student(string id, string name, string major, string cls, string dorm)
        : m_id(id), m_name(name), m_major(major), m_cls(cls), m_dorm(dorm) {}
    string getId() const { return m_id; }
    string getName() const { return m_name; }
    string getMajor() const { return m_major; }
    string getCls() const { return m_cls; }
    string getDorm() const { return m_dorm; }
    void setDorm(string dorm) { m_dorm = dorm; }
private:
    string m_id;    // 学号
    string m_name;  // 姓名
    string m_major; // 专业
    string m_cls;   // 班级
    string m_dorm;  // 宿舍号
};

// 宿舍类
class Dormitory {
public:
    Dormitory(string dorm, int capacity) : m_dorm(dorm), m_capacity(capacity) {}
    string getDorm() const { return m_dorm; }
    int getCapacity() const { return m_capacity; }
    bool isFull() const { return m_students.size() >= m_capacity; }
    bool addStudent(Student student) {
        if (isFull()) {
            return false;
        }
        m_students.push_back(student);
        return true;
    }
    bool removeStudent(Student student) {
        for (auto it = m_students.begin(); it != m_students.end(); ++it) {
            if (it->getId() == student.getId()) {
                m_students.erase(it);
                return true;
            }
        }
        return false;
    }
    vector<Student> getStudents() const { return m_students; }
private:
    string m_dorm;                   // 宿舍号
    int m_capacity;                  // 容量
    vector<Student> m_students;      // 住户信息
};

// 班级类
class Class {
public:
    Class(string cls) : m_cls(cls) {}
    string getCls() const { return m_cls; }
    vector<Student> getStudents() const { return m_students; }
    void addStudent(Student student) { m_students.push_back(student); }
private:
    string m_cls;                    // 班级编号
    vector<Student> m_students;      // 学生信息
};

// 宿舍管理系统
class DormitoryManager {
public:
    void addStudent(Student student) {
        m_students[student.getId()] = student;
        // 添加学生后，将其加入对应的班级中
        m_classes[student.getCls()].addStudent(student);
    }
    string getDormByStudentId(string id) const {
        if (m_students.find(id) != m_students.end()) {
            return m_students.at(id).getDorm();
        }
        return "";
    }
    string getAvailableDorm() const {
        for (auto it = m_dormitories.begin(); it != m_dormitories.end(); ++it) {
            if (!it->second.isFull()) {
                return it->second.getDorm();
            }
        }
        return "";
    }
    bool addStudentToDorm(Student student, string dorm) {
        if (m_dormitories.find(dorm) == m_dormitories.end()) {
            return false;
        }
        if (!m_dormitories[dorm].addStudent(student)) {
            return false;
        }
        // 添加学生后，更新其宿舍信息
        m_students[student.getId()].setDorm(dorm);
        return true;
    }
    bool removeStudentFromDorm(Student student) {
        if (m_dormitories.find(student.getDorm()) == m_dormitories.end()) {
            return false;
        }
        if (!m_dormitories[student.getDorm()].removeStudent(student)) {
            return false;
        }
        // 删除学生后，更新其宿舍信息
        m_students[student.getId()].setDorm("");
        return true;
    }
    vector<Dormitory> getDormitoriesByClass(string cls) const {
        vector<Dormitory> dorms;
        if (m_classes.find(cls) == m_classes.end()) {
            return dorms;
        }
        auto students = m_classes.at(cls).getStudents();
        for (auto it = m_dormitories.begin(); it != m_dormitories.end(); ++it) {
            for (auto st : students) {
                if (it->second.getStudents().size() > 0 && it->second.getStudents().at(0).getCls() == st.getCls()) {
                    dorms.push_back(it->second);
                    break;
                }
            }
        }
        return dorms;
    }
private:
    map<string, Student> m_students;                    // 学生信息
    map<string, Dormitory> m_dormitories;                // 宿舍信息
    map<string, Class> m_classes;                        // 班级信息
};

int main() {
    DormitoryManager manager;

    // 添加宿舍信息
    manager.addStudent(Student("001", "张三", "计算机科学与技术", "1班", "A101"));
    manager.addStudent(Student("002", "李四", "软件工程", "1班", ""));
    manager.addStudent(Student("003", "王五", "信息安全", "2班", "A102"));
    manager.addStudent(Student("004", "赵六", "物联网工程", "2班", ""));
    manager.addStudent(Student("005", "钱七", "人工智能", "3班", "A103"));
    manager.addStudent(Student("006", "孙八", "网络工程", "3班", ""));
    manager.addStudent(Student("007", "周九", "数字媒体技术", "4班", "A104"));
    manager.addStudent(Student("008", "吴十", "软件工程", "4班", ""));

    // 查询学生宿舍号
    cout << "学号为001的学生住在" << manager.getDormByStudentId("001") << "宿舍" << endl;

    // 添加学生到宿舍
    string dorm = manager.getAvailableDorm();
    if (dorm != "") {
        if (manager.addStudentToDorm(Student("009", "郑十一", "信息工程", "4班", ""), dorm)) {
            cout << "添加成功，学生住在" << dorm << "宿舍" << endl;
        }
        else {
            cout << "添加失败，宿舍已满" << endl;
        }
    }
    else {
        cout << "无可用宿舍" << endl;
    }

    // 换宿舍
    auto students = manager.getDormitoriesByClass("4班").at(0).getStudents();
    if (students.size() > 0) {
        auto student = students.at(0);
        string newDorm = manager.getAvailableDorm();
        if (newDorm != "") {
            if (manager.removeStudentFromDorm(student) && manager.addStudentToDorm(student, newDorm)) {
                cout << "换宿舍成功，学生" << student.getName() << "住在" << newDorm << "宿舍" << endl;
            }
            else {
                cout << "换宿舍失败" << endl;
            }
        }
        else {
            cout << "无可用宿舍" << endl;
        }
    }

    return 0;
}

在上述代码中，我们定义了`Student`、`Dormitory`和`Class`三个类来分别表示学生、宿舍和班级信息，然后定义了`DormitoryManager`类来管理学生、宿舍和班级信息，并实现了题目要求的各项功能。具体实现细节可以参考代码中的注释。