Question

Write a regular expression in C for

* A Shake is an ampersand '&' or a plus '+' or a '/' followed by

    an even number of letters 'a' through 'z' followed by an

    ampersand '&' or a plus '+' or a '/' BUT IT CANNOT END WITH

    THE SAME CHARACTER WITH WHICH IT STARTED. That is, if it

  begins with '&', it must end with '+' or '/', and so forth.

    (FYI: "an even number" means 0 or 2 or 4 or 6 or ..., which

     can also be stated as 2n, where n >= 0.)

Answer 1

ANSWER

&([a-z][a-z])*(\+|\/)|\+([a-z][a-z])*(&|\/)|\/([a-z][a-z])*(\+|&)

EXPLANATION

Any of the below 3

1. &([a-z][a-z])*(\+|\/)
2. \+([a-z][a-z])*(&|\/)
3. \/([a-z][a-z])*(\+|&)

([a-z][a-z])* is to get even # of letters 'a' through 'z'