cppPersonStructAdv

#include <iostream>

struct Person
{
    uint16_t id;
    char* fname;
    char* sname;
    uint8_t age;

    void init(uint16_t idP, const char* fnameP, const char* snameP, uint8_t ageP)
    {
        id = idP;

        size_t strLen{ strlen(fnameP) + 1 };
        fname = new char[strLen];
        strcpy_s(fname, strLen, fnameP);

        strLen = strlen(snameP) + 1;
        sname = new char[strLen];
        strcpy_s(sname, strLen, snameP);

        age = ageP;
    }

    void print(bool fnameFirst = true)
    {
        std::cout << id << " : " <<
            (fnameFirst ? fname : sname)
            << ' ' <<
            (fnameFirst ? sname :fname)
            << " - " << +age;
    }

    void setFName(const char* fnameP)
    {
        size_t pStrLen{ strlen(fname) + 1 };
        size_t strLen{ strlen(fnameP) + 1 };

        // if memory not limited
        if (pStrLen < strLen)
        {
            delete[] fname;
            fname = new char[strLen];
        }
        strcpy_s(fname, strLen, fnameP);
    }

    void setSName(const char* snameP)
    {
        size_t pStrLen{ strlen(sname) + 1 };
        size_t strLen{ strlen(snameP) + 1 };

        // if memory not limited
        if (pStrLen < strLen)
        {
            delete[] sname;
            sname = new char[strLen];
        }
        strcpy_s(sname, strLen, snameP);
    }

    void input()
    {
        char buf[50];
        std::cout << "Enter id: "; std::cin >> id;
        std::cin.ignore(100, '\n');

        std::cout << "Enter First name: ";
        std::cin.getline(buf, 49);
        setFName(buf);

        std::cout << "Enter Second name: ";
        std::cin.getline(buf, 49);
        setSName(buf);

        int ageP;
        std::cout << "Enter age: "; std::cin >> ageP;  age = ageP;
        std::cin.ignore(100, '\n');
    }

    void clear()
    {
        delete[] fname;
        delete[] sname;
    }
};

template <typename T>
void sort(T* arr, int arrSize,  bool(*criteria)(const T&, const T&))
{
    T copy;
    for (int head{ 0 }; head < arrSize; ++head)
    {
        for (int tail{ arrSize - 1 }; tail > head; --tail)
        {
            if (criteria(arr[tail], arr[head]))
            {
                copy = arr[tail];
                arr[tail] = arr[head];
                arr[head] = copy;
            }
        }
    }
}

bool personById(const Person& personA, const Person& personB)
{
    return personA.id < personB.id;
}

bool personByAge(const Person& personA, const Person& personB)
{
    return personA.age < personB.age;
}

int main()
{
    const int peopleCount{ 3 };
    Person people[peopleCount];

    people[0].init(21, "Ivan", "Petrov", 40);
    people[1].init(2, "Sidor", "Ivanov", 19);
    people[2].init(32, "Petr", "Sidorov", 33);

    for (int i{ 0 }; i < peopleCount; ++i)
    {
        people[i].print(); std::cout << '\n';
    }

    std::cout << "Sort by preson id:\n";

    sort(people, peopleCount, personById);

    for (int i{ 0 }; i < peopleCount; ++i)
    {
        people[i].print(); std::cout << '\n';
    }

    std::cout << "Sort by preson age:\n";

    sort(people, peopleCount, personByAge);

    for (int i{ 0 }; i < peopleCount; ++i)
    {
        people[i].print(); std::cout << '\n';
    }

    for (int i{ 0 }; i < peopleCount; ++i)
    {
        people[i].clear();
    }
    return 0;

}