Write a password authentication program using a Binary Search Tree for a fast
username search. Your program must meet the following requirements:
Before doing an authentication, read a file named “authen.pwd” that stores pairs of username and password.
Wait for a command from a user and respond accordingly. For example:
>Verify s1limth >Verify s1limth
passwd: 321cba passwd: abc123
Invalid Password! Password Confirmed!
Update the “authen.pwd” file before exiting the program.
The “authen.pwd” file must conform the following format:
Your program must be named “pwdauth.c” for the source code and
“pwdauth” for the executable.