bez pas

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

class UserAlreadyExistsException
{
    char* user;

public:
    UserAlreadyExistsException(char *user="")
    {
        this->user = new char[strlen(user) + 1];
        strcpy(this->user, user);
    }

    void message()
    {
        cout << "User with username " << user << " already exists!\n";
    }
};

class UserNotFoundException
{
    char* user;

public:
    UserNotFoundException(char *user="")
    {
        this->user = new char[strlen(user) + 1];
        strcpy(this->user, user);
    }

    void message()
    {
        cout << "User with username " << user << " was not found!\n";
    }
};

class FriendsLimitExceededException
{
    int n;

public:
    FriendsLimitExceededException(int n=0)
    {
        this->n = n;
    }

    void message()
    {
        cout << "Can't have more than " << n << " friends.\n";
    }
};

class User
{
private:
    char username[50];
    int age;
    int friends;
    static int maxFriends;

public:
    User(char *username = "", int age = 18) : age(age)
    {
        strcpy(this->username, username);
        friends = 0;
    }

    friend ostream &operator<<(ostream &os, const User &user)
    {
        os << "Username: " << user.username << " Age: " << user.age << " # of friends: " << user.friends;
        return os;
    }

    User &operator++()
    {
        if(friends >= maxFriends)
        {
            throw FriendsLimitExceededException(maxFriends);
        }

        ++friends;
        return *this;
    }

    User &operator--()
    {
        --friends;
        return *this;
    }

    static void setLimit(int _maxFriends)
    {
        maxFriends = _maxFriends;
    }

    friend class SocialNetwork;

    ~User() { }
};

class SocialNetwork
{
private:
    User *users;
    int n;
public:
    SocialNetwork()
    {
        n = 0;
        users = new User[n];
    }

    SocialNetwork &operator+=(User &u)
    {
        for(int i = 0; i < n; i++)
        {
            if(strcmp(u.username, users[i].username) == 0)
                throw UserAlreadyExistsException(u.username);
        }

        User *tmp = new User[n + 1];
        for (int i = 0; i < n; i++)
        {
            tmp[i] = users[i];
        }
        tmp[n++] = u;
        delete[] users;
        users = tmp;
        return *this;
    }

    void friendRequest(char *firstUsername, char *secondUsername)
    {
        bool b = false;
        for (int i = 0; i < n; i++)
        {
            if (strcmp(users[i].username, secondUsername) == 0)
            {
                b = true;
            }
        }

        if(b =- false)
        {
            throw UserNotFoundException(secondUsername);
        }

        for (int i = 0; i < n; i++)
        {
            if (strcmp(users[i].username, firstUsername) == 0)
            {

                for (int j = 0; j < n; j++)
                {
                    if (strcmp(users[j].username, secondUsername) == 0)
                    {
                        try
                        {
                            ++users[i];
                        }
                        catch(FriendsLimitExceededException& e)
                        {
                            e.message();
                            return;
                        }

                        try
                        {
                            ++users[j];
                        }
                        catch(FriendsLimitExceededException& e)
                        {
                            e.message();
                            --users[i];
                        }

                        return;
                    }
                }

            }
        }

        throw UserNotFoundException(firstUsername);
    }

    friend ostream &operator<<(ostream &os, const SocialNetwork &network)
    {
        os << "Users: " << endl;
        for (int i=0; i<network.n; i++)
        {
            os << network. users[i] << endl;
        }
        return os;
    }
};

int User::maxFriends = 3;

int main()
{
    SocialNetwork sn;
    int n;
    cin >> n;
    for (int i=0; i<n; i++)
    {
        char username[50];
        int age;
        cin >> username >> age;
        User u(username, age);

        try
        {
            sn += u;
        }
        catch(UserAlreadyExistsException& e)
        {
            e.message();
        }

    }

    cout << "Registration of users " << endl;
    cout << sn << endl;
    cout << "Friend requests " << endl;

    int friendships;
    cin >> friendships;
    for (int i=0; i<friendships; i++)
    {
        char username1[50], username2[50];
        cin >> username1 >> username2;

        try
        {
            sn.friendRequest(username1, username2);
        }
        catch(UserNotFoundException& e)
        {
            e.message();
        }

    }

    cout << sn << endl;

    cout << "CHANGE STATIC VALUE" << endl;

    int maxFriends;
    cin >> maxFriends;
    cin >> friendships;
    User::setLimit(maxFriends);
    for (int i=0; i<friendships; i++)
    {
        char username1[50], username2[50];
        cin >> username1 >> username2;

        try
        {
            sn.friendRequest(username1, username2);
        }
        catch(UserNotFoundException& e)
        {
            e.message();
        }
    }
    cout << sn;
    return 0;
}
---------------------------------------------------------------------------------------------------------------------------------------
#include<iostream>
#include<cstring>
using namespace std;

class UserAlreadyExistsException {
    char username[50];
public:
    UserAlreadyExistsException(char *user=" ")
    {
        strcpy (username,user);
    }
    void showMessage()
    {
        cout<<"User with username " <<username<<" already exists!"<<endl;
    }
//TODO
};

class UserNotFoundException {
    char username[50];
public:
    UserNotFoundException(char *name=" ")
    {
        strcpy (username,name);
    }
    void showMessage()
    {
        cout<<"User with username "<<username<<" was not found!"<<endl;
    }
};

class FriendsLimitExceededException {
    int number;
//TODO
public:
    FriendsLimitExceededException(int broj=0)
    {
        number=broj;
    }

    void showMessage()
    {
        cout<<"Can't have more than "<<number<<" friends."<<endl;
    }
};

class User {
private:
    char username[50];
    int age;
    int friends;


public:
    static int LIMIT;
    User(char *username = "", int age = 18) : age(age) {
        strcpy(this->username, username);
        friends = 0;
    }

    friend ostream &operator<<(ostream &os, const User &user) {
        os << "Username: " << user.username << " Age: " << user.age << " # of friends: " << user.friends;
        return os;
    }

    User &operator++() {
        ++friends;
        return *this;
    }
    static void setLimit(int a)
    {
        LIMIT=a;
    }

    friend class SocialNetwork;


};
int User::LIMIT=3;
class SocialNetwork {
private:
    User *users;
    int n;
public:
    SocialNetwork() {
        n = 0;
        users = new User[n];
    }

    SocialNetwork &operator+=(User &u) {

        for (int i=0;i<n;i++)
        {
            if (strcmp(users[i].username,u.username)==0)
            {
                throw UserAlreadyExistsException(u.username);
            }
        }
        User *tmp = new User[n + 1];
        for (int i = 0; i < n; i++) {
            tmp[i] = users[i];
        }
        tmp[n++] = u;
        delete[] users;
        users = tmp;
        return *this;
    }

    void friendRequest(char *firstUsername, char *secondUsername) {
        int flag1=0,flag2=0;
        for (int i = 0; i < n; i++) {
            if (strcmp(users[i].username, firstUsername) == 0) {
                flag1=1;
                for (int j = 0; j < n; j++) {
                    if (strcmp(users[j].username, secondUsername) == 0) {
                        flag2=1;
                        if (users[i].friends<User::LIMIT && users[j].friends<User::LIMIT){
                        ++users[i];
                        ++users[j];
                        }
                        else
                        throw FriendsLimitExceededException(User::LIMIT);
                        return;
                    }
                }
            }
        }
        if (flag2==0)
        {
            throw UserNotFoundException(secondUsername);
        }
        else if (flag1==0)
        {
            throw UserNotFoundException(firstUsername);
        }
    }

    friend ostream &operator<<(ostream &os, const SocialNetwork &network) {
        os << "Users: " << endl;
        for (int i=0;i<network.n;i++) {
            os << network. users[i] << endl;
        }
        return os;
    }
};


int main() {
    SocialNetwork sn;
    int n;
    cin >> n;
    for (int i=0;i<n;i++){
        char username[50]; int age;
        cin >> username >> age;
        try{ User u(username, age);
            sn += u;
        }
        catch (UserAlreadyExistsException e)
        {
            e.showMessage();
        }

    }

    cout << "Registration of users " << endl;
    cout << sn << endl;
    cout << "Friend requests " << endl;

    int friendships;
    cin >> friendships;
    for (int i=0;i<friendships;i++){
        char username1[50], username2[50];
        cin >> username1 >> username2;
        try{
            sn.friendRequest(username1, username2);

        }
        catch (UserNotFoundException e)
        {
            e.showMessage();
        }
        catch (FriendsLimitExceededException e)
        {
            e.showMessage();
        }
    }

    cout << sn << endl;

    cout << "CHANGE STATIC VALUE" << endl;

    int maxFriends;
    cin >> maxFriends;
    cin >> friendships;
    User::setLimit(maxFriends);
    for (int i=0;i<friendships;i++){
        char username1[50], username2[50];
        cin >> username1 >> username2;
        try{
            sn.friendRequest(username1, username2);

        }
        catch (UserNotFoundException e)
        {
            e.showMessage();
        }
        catch (FriendsLimitExceededException e)
        {
            e.showMessage();
        }

    }
    cout << sn;
    return 0;
}