Topic: Saturday 10001000
! and .
Throughout the task about 1000 queens http://www.sql.ru/forum/1270505/pyatnic -1-million
Let's admit arrangement of queens for a board 8x8 is found
Arrangement is saved in a DB in a type:
insert into queen8x8 (id, position) values (1, ' a1b5c8d6e3f7g2h4 ');
Thus we remember that this arrangement has brothers whom it is possible
To receive by a board turn on 90 degrees some times or a way
Board mirroring horizontally or vertically or .
We can according to the logic of application or on the trigger to add some more
Lines in queen8x8 which consider "turns" and "mirrors".
In the task also it is meant that we can do search of decisions on
To the partial coincidence. to find all combinations which correspond
To a certain start arrangement.
select * from queen8x8 where position like ' a1b5 __ d6e __ 7g2 __ ';
There was a question. We Can-whether create Domain-Index which will
To consider this moment? For the sake of place saving. For a board 10001000 cells.
P.S. Do not ask what for it it is necessary. Consider that it - simply brainstorming session
And the question "what for" is already transited and there is a question "as".