A note on browsers: I've run this successfully on chrome and safari (including an iphone). This does not run on firefox. I don't want to spend the time right now figuring out what's wrong. Everybody should have chrome at least for an emergency backup browser, right?
Enter a puzzle by one of the following methods...
<-- Explained below
You can type a puzzle into the textarea below, or copy and paste. Use a period for squares that have no constraint. I remove all whitespace. There's an example below the textarea for you to copy and paste.
.01.1.0.33.2.2.12. 1...2..3..2..0...2 ...1.2......2.3... .2.2..3.03.3..3.1. 2..0.1.1..2.2.1..1 2..3.2.1..1.1.2..1 .3.2..2.11.3..0.1. ...1.2......1.2... 3...1..1..3..2...3 .02.1.3.10.3.0.10.
After you solve a puzzle, you can click the "Next" button and it will check for another solution. It displays it if there is one. Otherwise it says "unsolvable". A proper slitherlink puzzle has only one solution, but an underconstrained one has more.
Here's a fun thing to do: Set the rows and columns to 2x2, then, without adding any constraints on the squares, click "Solve" then repeatedly click "Next". You can see all thirteen solutions.
Comments to doug[at]DougAndJean[dot]com