Editing Eight queens puzzle (section)

{{Short description|Mathematical problem set on a chessboard}}
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|The only symmetrical solution to the eight queens puzzle ([[up to]] [[rotation]] and [[reflection (mathematics)|reflection]])
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The '''eight queens puzzle''' is the problem of placing eight [[chess]] [[Queen (chess)|queen]]s on an 8×8 [[chessboard]] so that no two queens threaten each other; thus, a solution requires that no two queens share the same row, column, or diagonal.  There are 92 solutions.  The problem was first posed in the mid-19th century.  In the modern era, it is often used as an example problem for various [[computer programming]] techniques.

The eight queens puzzle is a special case of the more general '''''n'' queens problem''' of placing ''n'' non-attacking queens on an ''n''×''n'' chessboard.  Solutions exist for all [[natural number]]s ''n'' with the exception of ''n'' = 2 and ''n'' = 3.  Although the exact number of solutions is only known for ''n'' ≤ 27, the [[asymptotic analysis|asymptotic growth rate]] of the number of solutions is approximately (0.143 ''n'')<sup>''n''</sup>.