Word Ladders

Problem #151

Tags: games classical puzzle strings graphs

Who solved this?

Thanks a lot to Gaurav Kamath aka Moriarty for suggesting such an nice problem!

This popular game was probably invented by Lewis Carrol, the author of "Alice in Wonderland" at 1877.

You are given two words of the same length, and it is required to convert one into another with several steps. Each step consists of changing a single letter so that still existing vocabulary words are produced. Here is the ladder with goal of feeding HAY to the COW, for example:

HAY  ->  BAY  ->  BOY  ->  TOY  ->  TOW  ->  COW

Let us write a program searching for the shortest path between two words!

We will use our dictionary which you can download by this link: right-click and choose "Save as", please.

Our game will use words of 5 letters - any you will find in this list, including plurals like books and verbs in past like bowed.

Input data contains a number N of word pairs to process.
Next N lines contain two words each.
Answer should contain minimum length of the path between words for each pair - i.e. the total count of words in the chain, including starting and ending ones.


input data:
girls women
mayor clown

9 14

Here the following paths are possible:

women woken token tokes tikes tiles tills gills girls

mayor manor minor miner mines miles moles molts moots boots blots blows blown clown
You need to login to get test data and submit solution.