Permutations in C# Using Recursion

IntroductionRecently, while searching for a method to descramble a string of characters, I came across an article by Alexander Bogomolny, entitled ‘Counting and Listing All Permutations’. The article, from Interactive Mathematics Miscellany and Puzzles, introduces three separate algorithms all capable of generating a list of permutations for a given set of elements. To rewrite a word descrambler