Percolation/Mean cluster density: Difference between revisions

=={{header|Perl 6}}==

{{works with|Rakudo|2017.02}}

<lang perl6>my @perc;

my $fill = 'x';

enum Direction <DeadEnd Up Right Down Left>;

my $𝘒 = perctest(15);

.fmt("%-2s").say for @perc;

say "𝘱 = 0.5, 𝘔,𝘕 = 15, 𝘒 = $𝘒\n";

my $trials = 5;

for 10, 30, 100, 300, 1000 -> $𝘔x𝘕 {

my $𝘒 = ( [+] perctest($𝘔x𝘕) xx $trials ) / $trials;

say "𝘱 = 0.5, trials = $trials, 𝘔,𝘕 = $𝘔x𝘕, 𝘒 = $𝘒";

}

sub infix:<deq> ( $a, $b ) { $a.defined && ($a eq $b) }

sub perctest ( $grid ) {

generate $grid;

my $block = 1;

for ^$grid X ^$grid -> ($y, $x) {

fill( [$x, $y], $block++ ) if @perc[$y; $x] eq $fill

}

($block - 1) / $grid²;

}

sub generate ( $grid ) {

@perc = ();

@perc.push: [ ( rand < .5 ?? '.' !! $fill ) xx $grid ] for ^$grid;

}

sub fill ( @cur, $block ) {

@perc[@cur[1]; @cur[0]] = $block;

my @stack;

my $current = @cur;

loop {

if my $dir = direction( $current ) {

@stack.push: $current;

$current = move $dir, $current, $block

}

else {

return unless @stack;

$current = @stack.pop

}

}

sub direction( [$x, $y] ) {

( Down if @perc[$y + 1][$x] deq $fill ) ||

( Left if @perc[$y][$x - 1] deq $fill ) ||

( Right if @perc[$y][$x + 1] deq $fill ) ||

( Up if @perc[$y - 1][$x] deq $fill ) ||

DeadEnd

}

sub move ( $dir, @cur, $block ) {

my ( $x, $y ) = @cur;

given $dir {

when Up { @perc[--$y; $x] = $block }

when Down { @perc[++$y; $x] = $block }

when Left { @perc[$y; --$x] = $block }

when Right { @perc[$y; ++$x] = $block }

}

[$x, $y]

}

}

</lang>

{{out}}

<pre>. . 1 . 2 . . 3 . . . 4 . . .

2 2 . . 2 2 2 . 5 5 . 4 4 4 4

2 2 2 2 2 . 2 . 5 . . 4 . . 4

2 . 2 . 2 2 . . . . 4 4 4 . 4

. . . . . 2 . . . . 4 4 4 . .

6 6 6 6 . . 7 7 . . 4 . 4 4 .

6 . 6 . . . . . 4 4 4 4 4 . .

6 6 6 . . . 8 8 . 4 4 4 . . 4

6 . . . 9 . . . . . . 4 4 . 4

. 10 . 11 . . 12 12 . 4 . . 4 4 4

11 . 11 11 11 11 . 12 . 4 . 4 4 4 .

11 11 11 11 11 11 11 . . 4 4 . . 4 .

11 11 11 11 . 11 . . . 4 4 4 4 4 .

11 11 11 . 11 11 11 . . 4 4 4 4 . 13

. 11 11 . 11 11 . . . . 4 4 . 14 .

𝘱 = 0.5, 𝘔,𝘕 = 15, 𝘒 = 0.062222

𝘱 = 0.5, trials = 5, 𝘔,𝘕 = 10, 𝘒 = 0.114

𝘱 = 0.5, trials = 5, 𝘔,𝘕 = 30, 𝘒 = 0.082444

𝘱 = 0.5, trials = 5, 𝘔,𝘕 = 100, 𝘒 = 0.06862

𝘱 = 0.5, trials = 5, 𝘔,𝘕 = 300, 𝘒 = 0.066889

𝘱 = 0.5, trials = 5, 𝘔,𝘕 = 1000, 𝘒 = 0.0659358

</pre>