Problem I. 246. (September 2010)
I. 246. One can play the following game on a table of N×N cells. Initially all cells are blue. If you click on a cell, that cell and its side neighbours will change colour: blue cells will turn into red and red cells will turn into blue. The aim is to reach a given state of the board.
The file i246.html should be submitted together with any GIF, JPEG or PNG images that might be required, further, a short documentation (i246.txt or i246.pdf) of your solution, all compressed in a file i246.zip.
Deadline expired on October 11, 2010.