Nonograms from Invaders
A grid of squares is given. Each square must be filled in gray or left as white. The numbers to the right of the rows or under the columns are the lengths of the runs of gray squares in that row or column. (For example, 1, 2 means there is one gray square followed by two; the number of white squares separating them, before the first one, or after the last two is not given.) The aim is to find all gray squares. Click a square to change its color. You may use yellow to indicate that a square in definitely not gray.
Contributed by: Izidor Hafner (June 2013)
Open content licensed under CC BY-NC-SA
Determining whether a Nonogram has a solution and finding a solution is NP-complete , which means a difficult programming effort to solve either problems.
 S. Simpson. "Nonogram Solver." (Dec 20, 2011) www.comp.lancs.ac.uk/~simpsons/nonogram.
 Nonogram, http://en.wikipedia.org/wiki/Nonogram
 Jan N. van Rijn, Playing Games, The Complexity of Klondike, Mahjong, Nonograms and Animal Chess, Internal Report 2012–01 June 2012, Universiteit Leiden Opleiding Informatica