Levenshtein Distance

The Levenshtein distance is the minimum number of single character edits that are needed to transform one word into another. The available edits are deletion, insertion, or substitution of a single character.

For example the Levenshtein distance between “shine” and “train” is 4:

1. shine → shin (deletion of 'e')
2. shin → tshin (insertion of 't')
3. tshin → trhin (substitution of 's' for 'r')
4. trhin → train (substitution of 'h' for 'a')

For each pair of words per argument, print the Levenshtein distance on its own line.

External links: Rosetta Code, Wikipedia