Doublets is a type of word puzzle invented by Lewis Carroll (author of Alice in Wonderland). The goal is to change one word into another by adding, removing, or changing one letter at a time. The tricky part is that each intermediate step must also be a valid word.
If we think of words as vertices in a graph, then two words are connected by an edge if the EditDistance between them is exactly 1. Mathematica can then be used to solve Doublets with its shortestÃ¢ÂÂpath algorithm GraphPath.