edit-distance

I am trying to calculate edit distances of a string against a collection to find the closest match. My current problem is that the collection is very large (about 25000 items), so I had to narrow down the set to just strings of similar lengths but that still would only narrow it down to a few thousand strings and this still is very slow. Is there a datastructure that allows for a quick lookup of similar strings or is there another way I could address this problem? Sounds like a BK-tree might be what you want. Here's an article discussing them: http://blog.notdot.net/2007/4/Damn-Cool-Algorithms

I'm posting this in the spirit of answering your own questions. The question I had was: How can I implement the Levenshtein algorithm for calculating edit-distance between two strings, as described here , in Delphi? Just a note on performance: This thing is very fast. On my desktop (2.33 Ghz dual-core, 2GB ram, WinXP), I can run through an array of 100K strings in less than one second. function EditDistance(s, t: string): integer; var d : array of array of integer; i,j,cost : integer; begin { Compute the edit-distance between two strings. Algorithm and description may be found at either of

For a Data Structures project, I must find the shortest path between two words (like "cat" and "dog" ), changing only one letter at a time. We are given a Scrabble word list to use in finding our path. For example: cat -> bat -> bet -> bot -> bog -> dog I've solved the problem using a breadth first search, but am seeking something better (I represented the dictionary with a trie). Please give me some ideas for a more efficient method (in terms of speed and memory). Something ridiculous and/or challenging is preferred. I asked one of my friends (he's a junior) and he said that there is no