Code PHP, 1808 971 octets
Implémentation rapide et sale en PHP. D'abord force brute toutes les formes de tranche possibles, ensuite force brute toutes les positions et orientations des tranches.
Usage: cat pizza.txt | php pizza.php
Edit: réduction de la taille du code de plus de 45% en réécrivant l'algorithme en utilisant la récursivité plutôt que les boucles imbriquées. Cependant, cela mange de la mémoire (et des pizzas ;-)). Les pizzas plus grandes que 8x8 manqueront probablement de mémoire. La variante de boucle imbriquée peut facilement gérer n'importe quelle taille, mais est deux fois la taille du code.
<?php define('A',98);$n=fgets(STDIN);$d=array();$m=$u=str_pad('',A,'+');$s=0;while($g=fgets(STDIN)){$g=rtrim($g);assert(strlen($g)<=A-2);$s++;$m.='+'.str_pad(rtrim($g),A-2,' ').'+';for($l=0;$l<strlen($g);$l++)if($g[$l]=='#')$d[]=$s*A+$l+1;}$m.=$u;$r=count($d)/$n;x(reset($d),array(array()),0,0,0,0);die('No pizza for you!');function x($e,$c,$b,$a,$q,$t){global$r,$m,$d;$h=$a*A+$b;if(!in_array($e+$h,$d))return;if(in_array($h,$c[0]))return;$c[0][]=$h;$c[1][]=$b*A-$a;$c[2][]=-$a*A-$b;$c[3][]=-$b*A+$a;if(count($c[0])<$r)do{x($e,$c,$b+1,$a,$b,$a);x($e,$c,$b,$a+1,$b,$a);x($e,$c,$b-1,$a,$b,$a);x($e,$c,$b,$a-1,$b,$a);$v=($b!=$q||$a!=$t);$b=$q;$a=$t;}while($v);else w($c,$m,0,reset($d),0);}function w(&$p,$f,$o,$e,$i){global$n,$d;foreach($p[$i]as$h){$j=$e+$h;if(!isset($f[$j])||$f[$j]!='#')return;$f[$j]=chr(ord('0')+$o);}if(++$o==$n){for($k=A;$k<strlen($f)-A;$k++)if($k%A==A-1)echo PHP_EOL;else if($k%A)echo$f[$k];exit;}foreach($d as$j)for($i=0;$i<4;$i++)w($p,$f,$o,$j,$i);}
Code non golfé et documenté
Ci-dessous se trouve le code original documenté. Pour garder ma raison, j'ai travaillé avec le code source complet et j'ai écrit un script de minifieur simple pour supprimer les instructions comme assert()et error_reporting(), supprimer les crochets inutiles, renommer les variables, les fonctions et les constantes pour générer le code joué ci-dessus.
<?php
error_reporting(E_ALL) ;
// Width of each line of pizza shape.
// Constant will be reduced to single character by minifier,
// so the extra cost of the define() will be gained back.
define('WIDTH', 98) ;
// Read number of slices
$nrSlices = fgets(STDIN) ;
// Read pizza shape definition and
// convert to individual $positionList[]=$y*width+$x and
// linear (1D) $pizzaShape[$y*WIDTH+$x] with protective border around it.
//
// WARNING: assumes maximum pizza width of WIDTH-2 characters!
$positionList = array() ;
$pizzaShape = $headerFooter = str_pad('', WIDTH, '+') ;
$y = 0 ;
while ($line = fgets(STDIN))
{ $line = rtrim($line) ;
assert(strlen($line) <= WIDTH-2) ;
$y++ ;
$pizzaShape .= '+'.str_pad(rtrim($line), WIDTH-2, ' ').'+' ;
for ($x = 0 ; $x < strlen($line) ; $x++)
{ if ($line[$x] == '#') $positionList[] = $y*WIDTH + $x+1 ;
}
}
$pizzaShape .= $headerFooter ;
// Determine size of a slice
$sliceSize = count($positionList)/$nrSlices ;
// Build all possible slice shapes. All shapes start with their first part at
// the top of the pizza, and "grow" new parts in all directions next to the
// existing parts. This continues until the slice has the full size. This way
// we end up with all shapes that fit at the top of the pizza.
//
// The shape is defined as the offsets of the parts relative to the base
// position at the top of the pizza. Offsets are defined as linear offsets in
// the 1-D $pizzaShape string.
//
// For efficiency, we keep track of all four possible rotations while building
// the slice shape.
//
growSlice(reset($positionList), array(array()), 0, 0, 0, 0) ;
die('No pizza for you!') ;
function growSlice($basePosition, $shapeDeltas, $dx, $dy, $prevDx, $prevDy)
{ global $sliceSize, $pizzaShape, $positionList ;
// Check validity of new position
// Abort if position is not part of pizza, or
// if position is already part of slice
$delta = $dy*WIDTH + $dx ;
if (!in_array($basePosition+$delta, $positionList)) return ;
if (in_array($delta, $shapeDeltas[0])) return ;
// Add all four rotations to shapeDeltas[]
$shapeDeltas[0][] = $delta ;
$shapeDeltas[1][] = $dx*WIDTH - $dy ;
$shapeDeltas[2][] = -$dy*WIDTH - $dx ;
$shapeDeltas[3][] = -$dx*WIDTH + $dy ;
// Have we built a full slice shape?
if (count($shapeDeltas[0]) < $sliceSize)
{ // Grow shape either at current position or at previous position
do
{ growSlice($basePosition, $shapeDeltas, $dx+1, $dy, $dx, $dy) ;
growSlice($basePosition, $shapeDeltas, $dx, $dy+1, $dx, $dy) ;
growSlice($basePosition, $shapeDeltas, $dx-1, $dy, $dx, $dy) ;
growSlice($basePosition, $shapeDeltas, $dx, $dy-1, $dx, $dy) ;
$retry = ($dx != $prevDx || $dy != $prevDy) ;
$dx = $prevDx ;
$dy = $prevDy ;
} while ($retry) ;
} else
{ // Try to cover the entire pizza by translated and rotated instances of
// the slice shape.
fitSlice($shapeDeltas, $pizzaShape, 0, reset($positionList), 0) ;
}
}
function fitSlice(&$shape, $pizza, $id, $basePosition, $rotation)
{ global $nrSlices, $positionList ;
// Try to fit each part of the slice onto the pizza. If the part falls
// outsize the pizza, or overlays another slice we reject this position
// and rotation. If it fits, we mark the $pizza[] with the slice $id.
foreach ($shape[$rotation] as $delta)
{ $position = $basePosition + $delta ;
if (!isset($pizza[$position]) || $pizza[$position] != '#') return ;
$pizza[$position] = chr(ord('0')+$id) ;
}
// If $nrSlices slices have been fitted, we have found a valid solution!
// In that case, we display the solution and quit.
if (++$id == $nrSlices)
{ for ($pos = WIDTH ; $pos < strlen($pizza)-WIDTH ; $pos++)
{ if ($pos % WIDTH == WIDTH-1) echo PHP_EOL ;
else if ($pos % WIDTH) echo $pizza[$pos] ;
}
exit ;
}
// The current slice did fit, but we have still more slices to fit.
// Try all positions and rotations for the next slice.
foreach ($positionList as $position)
{ for ($rotation = 0 ; $rotation < 4 ; $rotation++)
{ fitSlice($shape, $pizza, $id, $position, $rotation) ;
}
}
}