N-queens minimum and knights and bishops: Difference between revisions
N-queens minimum and knights and bishops (view source)
Revision as of 16:46, 5 July 2022
, 1 year agoadded Raku programming solution
(→{{header|Wren}}: Added an embedded version.) |
(added Raku programming solution) |
||
Line 1,638:
. . . . . . N N . .
. . . . . . . . . .
</pre>
=={{header|Raku}}==
Due to the time it's taking only a subset of the task are attempted.
{{trans|Go}}
<lang perl6># 20220705 Raku programming solution
my (@board, @diag1, @diag2, @diag1Lookup, @diag2Lookup, $n, $minCount, $layout);
my %limits = ( my @pieces = <Q B K> ) Z=> 7,7,6; # >>=>>> 10;
my %names = @pieces Z=> <Queens Bishops Knights>;
sub isAttacked(\piece, \row, \col) {
given piece {
when 'Q' {
(^$n)>>.&{ return True if @board[$_;col] || @board[row;$_] }
return True if @diag1Lookup[@diag1[row;col]] ||
@diag2Lookup[@diag2[row;col]]
}
when 'B' {
return True if @diag1Lookup[@diag1[row;col]] ||
@diag2Lookup[@diag2[row;col]]
}
default { # 'K'
return True if (
@board[row;col] or
row+2 < $n && col-1 >= 0 && @board[row+2;col-1] or
row-2 >= 0 && col-1 >= 0 && @board[row-2;col-1] or
row+2 < $n && col+1 < $n && @board[row+2;col+1] or
row-2 >= 0 && col+1 < $n && @board[row-2;col+1] or
row+1 < $n && col+2 < $n && @board[row+1;col+2] or
row-1 >= 0 && col+2 < $n && @board[row-1;col+2] or
row+1 < $n && col-2 >= 0 && @board[row+1;col-2] or
row-1 >= 0 && col-2 >= 0 && @board[row-1;col-2]
)
}
}
return False
}
sub attacks(\piece, \row, \col, \trow, \tcol) {
given piece {
when 'Q' { row==trow || col==tcol || abs(row - trow)==abs(col - tcol) }
when 'B' { abs(row - trow) == abs(col - tcol) }
default { my (\rd,\cd) = ((trow - row),(tcol - col))>>.abs; # when 'K'
(rd == 1 && cd == 2) || (rd == 2 && cd == 1) }
}
}
sub storeLayout(\piece) {
$layout = [~] @board.map: -> @row {
[~] ( @row.map: { $_ ?? piece~' ' !! '. ' } ) , "\n"
}
}
sub placePiece(\piece, \countSoFar, \maxCount) {
return if countSoFar >= $minCount;
my ($allAttacked,$ti,$tj) = True,0,0;
for ^$n X ^$n -> (\i,\j) {
unless isAttacked(piece, i, j) {
($allAttacked,$ti,$tj) = False,i,j andthen last
}
last unless $allAttacked
}
if $allAttacked {
$minCount = countSoFar;
storeLayout(piece);
return
}
if countSoFar <= maxCount {
my ($si,$sj) = $ti,$tj;
if piece eq 'K' {
($si,$sj) >>-=>> 2;
$si = 0 if $si < 0;
$sj = 0 if $sj < 0;
}
for ($si..^$n) X ($sj..^$n) -> (\i,\j) {
unless isAttacked(piece, i, j) {
if (i == $ti && j == $tj) || attacks(piece, i, j, $ti, $tj) {
@board[i][j] = True;
unless piece eq 'K' {
(@diag1Lookup[@diag1[i;j]],@diag2Lookup[@diag2[i;j]])=True xx *
}
placePiece(piece, countSoFar+1, maxCount);
@board[i][j] = False;
unless piece eq 'K' {
(@diag1Lookup[@diag1[i;j]],@diag2Lookup[@diag2[i;j]])=False xx *
}
}
}
}
}
}
for @pieces -> \piece {
say %names{piece}~"\n=======\n";
loop ($n = 1 ; ; $n++) {
@board = [ [ False xx $n ] xx $n ];
unless piece eq 'K' {
@diag1 = ^$n .map: [ ^$n ] >>+>> * ;
@diag2 = ^$n .map: [ $n-1 ... 0 ] >>+>> * ;
@diag2Lookup = @diag1Lookup = [ False xx 2*$n-1 ]
}
$minCount = 2³¹ - 1; # golang: math.MaxInt32
my \nSQ = $n*$n;
for 1..nSQ -> \maxCount {
placePiece(piece, 0, maxCount);
last if $minCount <= nSQ
}
printf("%2d x %-2d : %d\n", $n, $n, $minCount);
if $n == %limits{piece} {
printf "\n%s on a %d x %d board:\n", %names{piece}, $n, $n;
say $layout andthen last
}
}
}</lang>
{{out}}
<pre>
Queens
=======
1 x 1 : 1
2 x 2 : 1
3 x 3 : 1
4 x 4 : 3
5 x 5 : 3
6 x 6 : 4
7 x 7 : 4
Queens on a 7 x 7 board:
. Q . . . . .
. . . . . Q .
. . . . . . .
Q . . . . . .
. . . . Q . .
. . . . . . .
. . . . . . .
Bishops
=======
1 x 1 : 1
2 x 2 : 2
3 x 3 : 3
4 x 4 : 4
5 x 5 : 5
6 x 6 : 6
7 x 7 : 7
Bishops on a 7 x 7 board:
. . . . . B .
. . B . . . .
. . B . B . .
. . . . . . B
. . . B . . .
. . . B . . .
. . . . . . .
Knights
=======
1 x 1 : 1
2 x 2 : 4
3 x 3 : 4
4 x 4 : 4
5 x 5 : 5
6 x 6 : 8
Knights on a 6 x 6 board:
K . . . . K
. . . . . .
. . K K . .
. . K K . .
. . . . . .
K . . . . K
</pre>
| |||