A palindrome is a string that reads the same forward ad well as backward. For example, "otto" and "never odd or even" are palindromes.

When determining if a string is a palindrome, we ignore characters that are not letters.

a) Give a recursive definition of a palindrome

b) What is the base case of your definition?

c) Write a recursive program based on your definition that repeatedly prompts the user for a string and then reports whether the string is a palindrome

d) Write an iterative program that does the same thing kepps asking until user indicates when to quit

e) Compare your two programs in terms of time and space efficency