HackerRank Inherited code solution in c++ programming

In this HackerRank Inherited code problem in the c++ programming language, You inherited a piece of code that performs username validation for your company's website. The existing function works reasonably well, but it throws an exception when the username is too short. Upon review, you realize that nobody ever defined the exception.

The inherited code is provided for you in the locked section of your editor. Complete the code so that, when an exception is thrown, it prints Too short: n (where n is the length of the given username).

HackerRank Inherited code problem solution in c++ programming.

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

/* Define the exception here */
class BadLengthException {
    private: 
        int n;
    public:
        BadLengthException(int errornumber) {
            n = errornumber;
        }
    
        int what() {
            return n;
        }
};


bool checkUsername(string username) {
    bool isValid = true;
    int n = username.length();
    if(n < 5) {
        throw BadLengthException(n);
    }
    for(int i = 0; i < n-1; i++) {
        if(username[i] == 'w' && username[i+1] == 'w') {
            isValid = false;
        }
    }
    return isValid;
}

int main() {
    int T; cin >> T;
    while(T--) {
        string username;
        cin >> username;
        try {
            bool isValid = checkUsername(username);
            if(isValid) {
                cout << "Valid" << '\n';
            } else {
                cout << "Invalid" << '\n';
            }
        } catch (BadLengthException e) {
            cout << "Too short: " << e.what() << '\n';
        }
    }
    return 0;
}

Second solution

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

/* Define the exception here */
class BadLengthException {
    private: 
        int n;
    public:
        BadLengthException(int errornumber) {
            n = errornumber;
        }
    
        int what() {
            return n;
        }
};


bool checkUsername(string username) {
    bool isValid = true;
    int n = username.length();
    if(n < 5) {
        throw BadLengthException(n);
    }
    for(int i = 0; i < n-1; i++) {
        if(username[i] == 'w' && username[i+1] == 'w') {
            isValid = false;
        }
    }
    return isValid;
}

int main() {
    int T; cin >> T;
    while(T--) {
        string username;
        cin >> username;
        try {
            bool isValid = checkUsername(username);
            if(isValid) {
                cout << "Valid" << '\n';
            } else {
                cout << "Invalid" << '\n';
            }
        } catch (BadLengthException e) {
            cout << "Too short: " << e.what() << '\n';
        }
    }
    return 0;
}