Eternity-Puzzle
The Eternity Puzzle is a matching game for one person out of 209 non-image, monochromatic parts to be placed on a regular dodecagon together. It was invented by the Englishman Christopher Monckton and distributed worldwide since June 1999 by the British company Racing Champions Ltd.. Caused a sensation in the high prize of one million pounds, which was advertised for the first submission of a correct solution. Within the first two years, sold the puzzle over 225,000 times. In the UK it was the best selling game of all time in the first month.
Description
The game consists of a square board with a twelve-sided recess having a diameter of about 60 cm. The 209 parts are flat, irregular, polygonal plastic plates, which carry all the same metallic - green hue. In particular, front and back are indistinguishable. Your measurements are between two and four centimeters.
Schematically, there are all parts of halved, the same size, equilateral triangles, each of which give twelve piece a puzzle piece. All parts are different from each other and none has a rotational or mirror symmetry.
Solution
With the help of several computers, the two Cambridge mathematicians Alex Selby and Oliver Riordan found on 15 May 2000, a solution, just a year after the game's release. Their victory was given to the rules set out on September 30th of the year known. Meanwhile, far more solutions are known, the total number is estimated to be at least 1080.
The solution strategies use evaluation functions to positions and assess individual stones (similar to a chess computer ) in order to minimize the number of positions to be examined, since the total number of positions would exceed all capacities. This seeks to achieve benign as possible interim solutions (benign hole shapes ) or problematic parts to use as early as possible.
Eternity II
The successor Eternity II is not yet solved, the prize money this time $ 2,000,000. This game consists of 256 equal squares that have imprinted on each edge of each one pattern. The solution is a 16 * 16 large square, wherein the pattern matching on adjacent squares. Although the puzzle also like its predecessor is NP-complete, so it has a comparable level of difficulty, there are (relative to the higher number of parts ) is much less possible solutions.