You are updating the username policy on your company's internal networking platform. According to the policy, a username is considered valid if all the following constraints are satisfied:
The username consists of to characters inclusive. If the username consists of less than or greater than characters, then it is an invalid username.
The username can only contain alphanumeric characters and underscores (_). Alphanumeric characters describe the character set consisting of lowercase characters , uppercase characters , and digits .
The first character of the username must be an alphabetic character, i.e., either lowercase character or uppercase character .
INVALID; Username length < 8 characters
INVALID; Username begins with non-alphabetic character
INVALID; '?' character not allowed
Update the value of regularExpression field in the UsernameValidator class so that the regular expression only matches with valid usernames.
The first line of input contains an integer , describing the total number of usernames. Each of the next lines contains a string describing the username. The locked stub code reads the inputs and validates the username.
The username consists of any printable characters.
For each of the usernames, the locked stub code prints Valid if the username is valid; otherwise Invalid each on a new line.