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# Eight Queen Puzzle

• #21
Aka "n queens puzzle"
• #22

What XD

• #23

This is an old puzzle. Consider the solution for 9 queens on a 9 by 9 or 81 square chess board. Inu fact, consider there is a neat solution (process) that will generate a solution for all n by n chessboards with n queens where n is an integer and odd. Can you prove there is a solution for all n by n chessboards with n queens where n is an integer and even. Of course this is where none of the queens can take each other. I was working with a computer programmer back in the early 1980's who was using the company's mainframe computer over the weekend to solve the case where n was 21. For that old computer using Fortran it took the whole weekend. He showed me the printout results which gave the solution and the computing time it took to get it. An hour later I gave him my proof of a method to generate a solution for every odd n. At the end I wrote:" Time to compute solution approx. 1 hr. Number of solutions generated infinite. Average computing time per solution approx ZERO.

• #24
omg that's hard
• #25
[COMMENT DELETED]
• #26

huh???

• #27

For those who talked about rotation symmetry , remember that when you rotate 90 degrees it is not symmetrical when the queen goes to different color square.

• #28

I have no Idea what he said

• #29

• #30

CONGRATS

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