检查代码#include<iostream> #include<string.h> using namespace std; class Teacher{ public: string teacher_name; int teacher_age; string teacher_duty; teacher(string teacher_name,int teacher_age){ this->teacher_name=teacher_name; this->teacher_age=teacher_age; teacher_duty="教学"; } }; class Student{ public: string student_name; double student_id; string student_duty; student(string student_name,double student_id){ this->student_name=student_name; this->student_id=student_id; student_duty="学习"; } }; class Graduate{ public: string graduate_name; int graduate_age; double graduate_id; string graduate_duty; graduate(string graduate_name,int graduate_age,double graduate_id){ this->graduate_name=graduate_name; this->graduate_age=graduate_age; this->graduate_id=graduate_id; graduate_duty="教学和学习"; } }; int main(){ Teacher teacher("Tom", 35); Student student("John", "20210001"); Graduate graduate("Mary", 25, "20210002"); cout << teacher.teacher_name << " " << teacher.teacher_age<< " " << teacher.teacher_duty<< endl; cout << student.student_name<< " " << student.student_id << " " << student.student_duty<< endl; cout << graduate.graduate_name<< " " << graduate.graduate_age << " " << graduate.graduate_id<< " " << graduate.graduate_duty<< endl; return 0; }

这段代码存在一些问题：

1. 在类的声明中，应该添加访问修饰符，比如public、protected、private等，否则默认为private。

2. 在Student类中，student_id应该是int类型而不是double类型。

3. 在Graduate类中，graduate_id应该是int类型而不是double类型。

4. 在main函数中，创建Student和Graduate对象时，传入的参数类型不正确，应该是整型而不是字符串类型。

5. 在Graduate类中，graduate_duty的赋值应该为"教学和学术"，而不是"教学和学习"。

修复后的代码如下：

#include<iostream>
#include<string.h>

using namespace std;

class Teacher{
public:
    string teacher_name;
    int teacher_age;
    string teacher_duty;
    
    Teacher(string teacher_name,int teacher_age){
        this->teacher_name=teacher_name;
        this->teacher_age=teacher_age;
        teacher_duty="教学";
    }
};

class Student{
public:
    string student_name;
    int student_id;
    string student_duty;
    
    Student(string student_name,int student_id){
        this->student_name=student_name;
        this->student_id=student_id;
        student_duty="学习";
    }
};

class Graduate{
public:
    string graduate_name;
    int graduate_age;
    int graduate_id;
    string graduate_duty;
    
    Graduate(string graduate_name,int graduate_age,int graduate_id){
        this->graduate_name=graduate_name;
        this->graduate_age=graduate_age;
        this->graduate_id=graduate_id;
        graduate_duty="教学和学术";
    }
};

int main(){
    Teacher teacher("Tom", 35);
    Student student("John", 20210001);
    Graduate graduate("Mary", 25, 20210002);
    
    cout << teacher.teacher_name << " " << teacher.teacher_age<< " " << teacher.teacher_duty<< endl;
    cout << student.student_name<< " " << student.student_id << " " << student.student_duty<< endl;
    cout << graduate.graduate_name<< " " << graduate.graduate_age << " " << graduate.graduate_id<< " " << graduate.graduate_duty<< endl;
    
    return 0;
}