1. Compute the "distance" from one string to another in terms of 3 different operations.
   • inserting a character
   • deleting a character
   • swapping substrings

Are you talking about Levensthein distance? From the documentation of Text::Levensthein:

The Levenshtein edit distance is a measure of the degree of proximity between two strings. This distance is the number of substitutions, deletions or insertions ("edits") needed to transform one string into the other one (and vice versa). When two strings have distance 0, they are the same.

There is also a Text::LevenstheinXS. I have not used any of these modules myself, though, so I can't say anything more about their qualities.

Perhaps this might save you some work. Good luck!

pernod
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Mischief. Mayhem. Soap.