Problem
1. Write a program to convert a binary number specified as argument to decimal.
2. Write a program that looks up /etc/passwd and /etc/group and prints
(i) the highest UID,
(ii) the login name, real name, and GID (both number and name) of that user.
3. Write a program that populates an array named weekday from the string Sun Mon Tue Wed Thu Fri Sat, and then prints each day in uppercase.