DOMINO PUZZLE
Imagine the full set of dominoes is randomly
arranged into 7x8 rectangle. Then the resulting picture is
being redrawn in a sheet of paper with all borders between
dominoes cleared. You must restore the original configuration.
Of course, not each of 1292697 ways to tile 7x8 rectangle will
give the correct solution, but generally, the solution will
not be unique.
History
Martin Gardner claims that this game was designed by Lech Pianowsky. The
description of the game was published in one of his Sci. Am. puvlicatons
in seventies, or so.