杏吧原创

Thanks to a combination of computer graphics and clever mathematical short
cuts, crossword puzzle fans can finally play the game in three
dimensions鈥攁nd on the Internet, too. A new Internet company called Horizon
began releasing the puzzles at www.3dcrossword.com last month. Using a special
browser plug-in, players can solve a cube-like crossword puzzle. Words run not
only up and down, but also through the cube, which you rotate in 3D space as you
solve each line. Horizon鈥檚 idea is to sell the puzzles as kooky content for
other websites.

鈥淚鈥檝e been around crosswords for 20 years, and this is the first time I鈥檝e
heard a 3D crossword even rumoured to be in existence. Even a 2D crossword is
difficult to construct mathematically,鈥� says Timothy Parker, who constructs
crosswords for the Universal Press Syndicate. Parker is negotiating with Horizon
to edit its 3D crosswords.

Good human crossword constructors can create a newspaper crossword puzzle
in a matter of hours. But add the third dimension, and the task is virtually
impossible. Horizon鈥檚 chief executive Dan Moran says he knows someone who
hand-constructed a 3D crossword in a seven-by-seven-by-seven cube鈥攂ut it
took five years.

Even a computer might find the problem beyond it, since the number of
combinations is so large. Crunching through all the combinations in a 10-space
cube could take years, even for a fast computer. But Moran says the company
created algorithms that allow the computer to guess when it鈥檚 labouring at a
dead end, or to rearrange the spaces to make a puzzle easier to create. Using
the algorithms, Horizon鈥檚 computer can spit out a new puzzle about every 15
minutes.

All Horizon has to do now is create the clues for the puzzles, which still
have to be handwritten. Parker says he wants to make sure the puzzles conform to
the same high standards as the 2D world, such as not having too many obscure
words.