There's a nice bitmap based approach for enumerating n-queen placements described at https://blog.cloudboost.io/bitwise-n-queens-in-a-tweet-9251ef0e4379 https:

There's a nice bitmap based approach for enumerating n-queen placements described at https://blog.cloudboost.io/bitwise-n-queens-in-a-tweet-9251ef0e4379 https://blog.cloudboost.io/bitwise-n-queens-in-a-tweet-9251e...