用c++实现：学校（School）拥有多名教师（Teacher）（提示：可以使用指针数组或者指向指针的指针），每名教师知道自己所在的学校。

以下是用 C++ 实现的代码：

#include <iostream>

using namespace std;

class School;  // 前向声明

class Teacher {
private:
    string name;
    School *school;

public:
    Teacher(string n, School *s) {
        name = n;
        school = s;
    }

    string getName() {
        return name;
    }

    void setName(string n) {
        name = n;
    }

    School* getSchool() {
        return school;
    }

    void setSchool(School *s) {
        school = s;
    }
};

class School {
private:
    string name;
    Teacher **teachers;
    int numTeachers;

public:
    School(string n, int num) {
        name = n;
        numTeachers = num;
        teachers = new Teacher*[numTeachers];
        for (int i = 0; i < numTeachers; i++) {
            teachers[i] = NULL;
        }
    }

    string getName() {
        return name;
    }

    void setName(string n) {
        name = n;
    }

    int getNumTeachers() {
        return numTeachers;
    }

    void setNumTeachers(int num) {
        numTeachers = num;
    }

    Teacher** getTeachers() {
        return teachers;
    }

    void setTeacher(int index, Teacher *t) {
        teachers[index] = t;
    }
};

int main() {
    School *school = new School("ABC School", 3);
    Teacher *teacher1 = new Teacher("Tom", school);
    Teacher *teacher2 = new Teacher("Jack", school);
    Teacher *teacher3 = new Teacher("Mary", school);

    school->setTeacher(0, teacher1);
    school->setTeacher(1, teacher2);
    school->setTeacher(2, teacher3);

    for (int i = 0; i < school->getNumTeachers(); i++) {
        cout << school->getTeachers()[i]->getName() << " works at " << school->getName() << endl;
    }

    return 0;
}

这个程序定义了两个类：`School` 和 `Teacher`。其中，`Teacher` 类包含了教师的姓名和所在的学校，`School` 类包含了学校的名称和教师数组，以及与教师相关的一些函数。在 `main()` 函数里，我们创建了一个学校和三个教师，并将这三个教师添加到学校中。最后，我们遍历教师数组，输出每个教师的姓名和所在的学校。