定义一个人员CPerson类，包含数据成员年龄和姓名，定义一个CPerson类的派生类教师CTeacher类，包含数据成员专业和职称。分别为两个类定义带参数的构造函数初始化，再分别定义display（）函数输出信息。将display()函数定义为虚函数，并用CPerson类的指针分别指向CPerson类和CTeacher类的对象，实现多态。编写主函数测试如果年龄小于26岁，则提示"Input Error!"并结束程序。。

好的，下面是代码实现：

#include <iostream>
#include <string>
using namespace std;

class CPerson {
protected:
    int age;
    string name;

public:
    CPerson(int a, string n): age(a), name(n) {}
    virtual void display() {
        cout << "姓名：" << name << endl;
        cout << "年龄：" << age << endl;
    }
};

class CTeacher : public CPerson {
private:
    string major;
    string jobTitle;

public:
    CTeacher(int a, string n, string m, string j): CPerson(a, n), major(m), jobTitle(j) {}
    void display() {
        cout << "姓名：" << name << endl;
        cout << "年龄：" << age << endl;
        cout << "专业：" << major << endl;
        cout << "职称：" << jobTitle << endl;
    }
};

int main() {
    int age;
    string name, major, jobTitle;
    cout << "请输入姓名：";
    cin >> name;
    cout << "请输入年龄：";
    cin >> age;
    if (age < 26) {
        cout << "Input Error!" << endl;
        return 0;
    }
    cout << "请输入专业：";
    cin >> major;
    cout << "请输入职称：";
    cin >> jobTitle;

    CPerson* person = new CPerson(age, name);
    person->display();
    cout << endl;

    CTeacher* teacher = new CTeacher(age, name, major, jobTitle);
    CPerson* person2 = teacher;
    person2->display();

    delete person;
    delete teacher;

    return 0;
}

在上面的代码中，我们在输入年龄时添加了判断，如果年龄小于 26 岁，则输出错误提示并结束程序。