A puzzle in which one has to place eight queens on a chessboard such that no queen is attacking any other, i.e. no two queens occupy the same row, column or diagonal. One may have to produce all possible such configurations or just one.
It is a common students assignment to devise a program to solve the eight queens puzzle. The brute force algorithm tries all 64*63*62*61*60*59*58*57 = 178,462,987,637,760 possible layouts of eight pieces on a chessboard to see which ones meet the criterion. More intelligent algorithms use the fact that there are only ten positions for the first queen that are not reflections of each other, and that the first queen leaves at most 42 safe squares, giving only 10*42*41*40*39*38*37*36 = 1,359,707,731,200 layouts to try, and so on.
The puzzle may be varied with different number of pieces and different size boards.
[eyts] /eɪts/ noun, (used with a singular verb) 1. . [eyt] /eɪt/ noun 1. a cardinal number, seven plus one. 2. a symbol for this number, as 8 or VIII. 3. a set of this many persons or things, as the crew of an eight-oared racing shell. 4. a playing card the face of which […]
- Eightsome reel
/ˈeɪtsəm/ noun 1. a Scottish dance for eight people
[eyt-spot] /ˈeɪtˌspɒt/ noun, Slang. 1. a playing card the face of which bears eight pips.
/ˈeɪtvəʊ/ noun (pl) -vos 1. (bookbinding) another word for octavo