TetraVex

Tetravex is a kind of a puzzle, wherein a quantity of the square parts are to be arranged to a large square. Each of the four sides of a part is labeled with a number (old Greek τετρα = four, latin VEXO = shatter ). Adjacent sides need to be Lösungsanordung have the same number.

Strategy

For n parts, there are n! possible arrangements; with 9 parts of this are 362,880th There can be several, or no solutions. For which there is 362880 * 40 ( 362880 is the number of possibilities for the arrangement of the stones and as each stone having four sides on all 10 different digits can ( four sides times 10 digits = 40), there are 14,515,200 different ways to play for a 9 * 9 Tetravex.

A simple backtracking strategy would be to fill the fields of the solution square from one corner to the opposite with parts. Come here two different numbers next to each other to lie, the last specified part will be replaced by an alternative. If there is no alternative but the assignment of the next to the last edited field to be replaced, and so on. In this way need not be completely specified all the possible combinations.

A heuristic to limit the size of any problem can is to identify edge and corner pieces. For example, if a portion above a 7, but no other part below a 7, so this part must be placed at the top of the solution square.

Variants

Usually played with 9 parts. Often, of 4 or 16er jigsaw puzzles are. Even a non- square array is possible. Since for every game new parts are required, Textravex is usually implemented as a computer game. In most cases the numbers from 0 to 9 are used, but it can be used any couples about even colors, images or words.

Implementations

The oldest implementation as a computer game comes from the Microsoft Windows Entertainment Pack 3 Another version is an open source game for GNOME. There are also versions as a browser game.