Good morning everyone,
There was a mistake in the project description: on 3D chessboard, two queens should not share two common coordinates in order to avoid attacking each other along straight lines (ignoring diagonals here). The description has been modified accordingly on Moodle; in the first version, it was wrongly stated that they should not share one coordinate only, which makes solving the N^2 queens problem completely impossible.
There was a mistake in the project description: on 3D chessboard, two queens should not share two common coordinates in order to avoid attacking each other along straight lines (ignoring diagonals here). The description has been modified accordingly on Moodle; in the first version, it was wrongly stated that they should not share one coordinate only, which makes solving the N^2 queens problem completely impossible.
Example:
Two queens in position (1,2,3) and position (1,3,5) do not attack each other along a straight line.
But two queens in position (1,2,3) and (1,2,4) attack each other along the vertical straight line in position (x=1,y=2)
Best,
Olivier
