Hi Neil,
Thanks for sending the code. I've only had chance to have a brief look
so far, but i've found a point you may want to look at:
In your QTk descriptions for the board size box and the select column
box,
numberentry(
min:0
max:16
init: 0
handle:E
return:R
bg:white
)
are you sure the minimum value is 0? Do you want your program to
attempt to display a board size of 0?
Regards
Mark
Neil Munro wrote:
I have a few more issues with my n queens program but
I have been making progress :)
First On an 8x8 board The program can discover what the missing
elements are, but for some reason does not add the final element to the
list, which it should then return.
Secondly I have a limit on the expected size of the board the upper
limit is 16x16 board but when I enter 16 in the board selection dialog
box, the n-queens algorithm will only run to a maximum of 12 queens, I
do not know if this is linked to my first problem.
Further testing shows on an 8x8 grid with 7 of the queens provided the
program cant find the final element, yet increase the board size to 16
(and although it will only run to 12) you will get the 8th queen
position. Below are my functions if anyone could help me work out where
my last few issues are, I would be grateful.
fun {Queens L N}
if {GetLengthOfList L} == N then
{Browse L}
L
else
{Browse L}
{Queens {Revise 0|L} N}
end
end
fun {GetLengthOfList L}
case L of H|T then
1+{GetLengthOfList T}
else
0
end
end
fun {Revise L}
case L of H|T then
if H == BoardSize then {Revise T}
else N = {GetLengthOfList L} in
if {Threaten {BuildList T} H+1#N} then {Revise H+1|T}
else {AddToList H+1#N T}
end
end
else nil
end
end
fun {BuildList L}
case L of H|T then
%{Browse H.1#{GetLengthOfList L}}
H.1#{GetLengthOfList L}|{BuildList T}
else
nil
end
end
_________________________________________________________________________________
mozart-users mailing list [email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
--
Mark Richardson
Final year undergraduate
University of Teesside
|
_________________________________________________________________________________
mozart-users mailing list
[email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
