usernameExsist function c++ Object-orienten progrmming

I have a class:

class Account {
private:
    string name;
    unsigned int age;
    string username;
    string password;
};

In my main program I need to make a bool usernameExsist(Account* userAccount, Account* acountList[], int numberOfElements) function that returns true if the name is found. But I have problems with the arrays and the implementation.I entered some information in the class: Account first=Account("Max", 18,"maxx34","12345adc");Can someone help me with the implementation?! Thanks.