编写一个程序，定义抽象基类Shape，由它派生出5个派生类：Circle、Square、Rectangle、Trapezoid、Triangle。用虚函数分别计算几种图形面积，并求它们之和。2．某学校对教师每月工资的计算规定如下：固定工资+课时补贴。教授的固定工资为5000元，每个课时补贴50元。副教授的固定工资为3000元，每个课时补贴30元。讲师的固定工资为2000元，每个课时补贴20元。定义教师抽象类，派生不同职称的教师类，编写程序求若干个教师的月工资

好的，这是两个问题，我分别回答。

第一个问题，可以参考下面的代码实现：

#include <iostream>
using namespace std;

class Shape {
public:
    virtual double area() = 0;
};

class Circle : public Shape {
private:
    double radius;
public:
    Circle(double r) {
        radius = r;
    }
    virtual double area() {
        return 3.14 * radius * radius;
    }
};

class Square : public Shape {
private:
    double side;
public:
    Square(double s) {
        side = s;
    }
    virtual double area() {
        return side * side;
    }
};

class Rectangle : public Shape {
private:
    double length, width;
public:
    Rectangle(double l, double w) {
        length = l;
        width = w;
    }
    virtual double area() {
        return length * width;
    }
};

class Trapezoid : public Shape {
private:
    double upper_base, lower_base, height;
public:
    Trapezoid(double ub, double lb, double h) {
        upper_base = ub;
        lower_base = lb;
        height = h;
    }
    virtual double area() {
        return (upper_base + lower_base) * height / 2;
    }
};

class Triangle : public Shape {
private:
    double base, height;
public:
    Triangle(double b, double h) {
        base = b;
        height = h;
    }
    virtual double area() {
        return base * height / 2;
    }
};

int main() {
    Shape *shapes[5];
    shapes[0] = new Circle(2.0);
    shapes[1] = new Square(3.0);
    shapes[2] = new Rectangle(4.0, 5.0);
    shapes[3] = new Trapezoid(3.0, 5.0, 4.0);
    shapes[4] = new Triangle(4.0, 3.0);

    double total_area = 0.0;
    for (int i = 0; i < 5; i++) {
        total_area += shapes[i]->area();
    }

    cout << "Total area: " << total_area << endl;

    return 0;
}

第二个问题，可以参考下面的代码实现：

#include <iostream>
using namespace std;

class Teacher {
public:
    virtual double get_salary() = 0;
};

class Professor : public Teacher {
public:
    virtual double get_salary() {
        return 5000.0;
    }
};

class AssociateProfessor : public Teacher {
public:
    virtual double get_salary() {
        return 3000.0;
    }
};

class Lecturer : public Teacher {
public:
    virtual double get_salary() {
        return 2000.0;
    }
};

int main() {
    Teacher *teachers[3];
    teachers[0] = new Professor();
    teachers[1] = new AssociateProfessor();
    teachers[2] = new Lecturer();

    double total_salary = 0.0;
    for (int i = 0; i < 3; i++) {
        int hours;
        cout << "Please input the hours of teacher " << i + 1 << ": ";
        cin >> hours;
        total_salary += teachers[i]->get_salary() + hours * (i + 1) * 10.0;
    }

    cout << "Total salary: " << total_salary << endl;

    return 0;
}

注意：上述代码只是提供了一种实现方式，并不代表是最优解，可以根据实际情况进行修改和优化。