Problem Overview
The focus of the assignment is to implement a word connection game that has been played in one variation or another for over 130 years. The object of the game is to transform a start word into an end word of the same length by a sequence of steps, each of which consists of a one-letter change to the current word that results in another legal word. Charles Lutwidge Dodsgon (Lewis Carroll) invented this game and called it “Doublets.” It’s now more commonly known as “Word Ladders” .
Consider the following examples.
clash, flash, flask, flack, flock, clock, crock, crook, croon, crown, clown cat, can, con, cog, dog cat, bat, eat, fat, gat, hat
Each is a valid word ladder from the start word to the end word since the start and end words are the same length and each word in between is exactly one letter different from the previous word.
The game is usually played so that each player tries to find the shortest word ladder between two words. The shortest ladder would, of course, depend on the lexicon, or list of words, being used for the game. Using the SOWPODS word list (see Provided Resources), word ladders with minimum length for the start-end pairs above would be:
clash, class, claws, clows, clown cat, cot, dot, dog cat, hat
Requirements
1
Provided Resources
You are provided with the following resources as part of the assignment.
• The WordLadderGame interface.
• The Doublets class (a shell, not complete).
• A jar file, WordLists.jar. This jar file contains the following text files that you are allowed to use as lexicons for the Doublets class: CSW12.txt (the word list used in international Scrabble tournaments), OWL.txt (the word list used in North American Scrabble tournaments), sowpods.txt (SOWPODS— a commonly used combination of the CSW list and the OWL list), words.txt (the word list supplied in UNIX distributions), small.txt (a relatively small subset of the SOWPODS list), tiny.txt (a truly tiny word list), and names.txt (a list of first names used in the United States from 1880-2012, provided by the U.S. Social Security Administration ).
• A sample client, ExampleClient.java. This driver class illustrates basic calls to the methods, and it also demonstrates how to associate a text file contained in WordList.jar with an InputStream object.
