How to store several structures in another?

Question

How to store several structures in another?

Navigation

#1 by (0 votes)

0

I have these three structures in c ++:

struct Profesores{
    char nombre[30];
    double ci;
}prof[100];

struct Asignaturas{
    char nombre[30];
    char id[30];
    struct Profesores p_prof;
}asig[100];


struct Alumno{
    char nombre[30];
    double ci;
    struct Asignaturas p_asig;
}alum[100],*p_alum=alum;

And for a university project we were asked that the program should ask the user how many students he wants to register, and for each student to ask how many subjects he wants to register, the same for the teachers of the subject, and I can not find the way to place a kind of arrangement of structures nested within another structure (students).

Since it is our first project in C ++ so far the knowledge I have is of conditions, arrangements, functions, a bit of pointers (I still do not use it very well) .. then that is my problems like storing several structures in one alone, asking the user how many structures you want to link.

c++ estructuras

asked by Marcel Salazar 07.07.2018 в 00:37

source

1 answer

I made a resize of a partition and I lost the data !! how can I recover it! User roles firebase vuejs

score 0 · Answer 1

Before sharing my suggestion with you, I would like to suggest other corrections. In C ++ the keyword struct is not part of the type, the struct are already a type per se , so it is not necessary to prefix this keyword to define instances of that data, your definitions of types could look like this:

struct Profesores{
    char nombre[30];
    double ci;
};

struct Asignaturas{
    char nombre[30];
    char id[30];
    Profesores p_prof;
};

struct Alumno{
    char nombre[30];
    double ci;
    Asignaturas p_asig;
};

Thus, the type Asignaturas stores an instance of type Profesores while the type type Alumno stores an instance of type Asignaturas .

If you want to store text, the most convenient is to use std::string , which will allow you to store arbitrary length texts (no limit to 29 characters), your type definitions could look like this:

struct Profesores{
    std::string nombre;
    double ci;
};

struct Asignaturas{
    std::string nombre;
    std::string id;
    Profesores p_prof;
};

struct Alumno{
    std::string nombre;
    double ci;
    Asignaturas p_asig;
};

On the other hand, your nomenclature is very confusing, you use the plural to refer to unique concepts; There is no number match! It's as if you said " Do you like my car s ? It's that the there !". In general you should use the singular for types and the plural for collections, your type definitions could look like this:

struct Profesor{
    std::string nombre;
    double ci;
};

struct Asignatura{
    std::string nombre;
    std::string id;
    Profesor p_prof;
};

struct Alumno{
    std::string nombre;
    double ci;
    Asignatura p_asig;
};

Now let's see your statements:

For each student, they will ask how many subjects they want to register, the same for teachers.

If I understand it correctly, teachers and students are exactly the same (they contain subjects) so a priori a different class is not necessary:

struct Asignatura {
    std::string nombre;
    std::string id;
};

struct Persona {
    std::string nombre;
    std::string id;
    std::vector<Asignatura> asignaturas;
};

The type Persona can be a student or a teacher, if you need to differentiate them you can use two different types (as you did before) or add a list that internally distinguishes them:

enum Tipo {
    Alumno,
    Profesor,
};

struct Persona {
    Tipo tipo;
    std::string nombre;
    std::string id;
    std::vector<Asignatura> asignaturas;
};

To fulfill the premise that both students and teachers must register subjects, I added a std::vector of Asignatura , to register elements you could do something similar to this:

Persona crear_persona()
{
    Tipo t;
    std::string nombre, id;

    // Preguntar si es alumno o profesor
    // ...

    // Preguntar el nombre
    // ...

    // Preguntar el id
    // ...

    return {t, nombre, id};
}

And to add subjects, you could also create an auxiliary function:

Asignatura crear_asignatura()
{
    std::string nombre, id;

    // Preguntar el nombre
    // ...

    // Preguntar el id
    // ...

    return {nombre, id};
}

With these auxiliary functions your code could look like this:

int main() {
    int asignaturas;

    Persona p = crear_persona();
    std::cout << "¿Cuantas asignaturas tiene asignadas " << p.nombre << "?\n";
    std::cin >> asignaturas;

    for (int asignatura = 0; asignatura != asignaturas; ++asignatura) {
        p.asignaturas.push_back(crear_asignatura());
    }

    return 0;
}