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use strict;
use warnings;
#------------------------------------------------------------------------------
=pod
Surround the array and consider:
* 1: node was visited
* 0: node has to be visited
Example 6x4 matrix => converted to 8x6 (matrix_aux)
1 1 1 1 1 1
1 0 0 0 0 1
1 0 0 0 0 1
1 0 0 0 0 1
1 0 0 0 0 1
1 0 0 0 0 1
1 0 0 0 0 1
1 1 1 1 1 1
Algorithm idea:
- move in the current direction, visiting "0" nodes
- change "0" node by "1"
- when "1" node is reached, go back and change direction
- if all nodes are visited, end
=cut
#------------------------------------------------------------------------------
sub spiral_matrix {
my @matrix = @_;
my $aux_matrix = [];
my @result = ();
my $size_x = scalar $matrix[0]->@*;
my $size_y = scalar @matrix;
my $nodes = $size_x * $size_y;
push $aux_matrix->@*, [ (1) x ($size_x+2) ];
push $aux_matrix->@*, [ 1, (0) x $size_x, 1 ] for ( 1 .. $size_y );
push $aux_matrix->@*, [ (1) x ($size_x+2) ];
my $direction = 0;
my $visits = 0;
my ($cx, $cx_1) = (0, 0);
my ($cy, $cy_1) = (1, 1);
while( $visits < $nodes ) {
$direction == 0 && $cx++;
$direction == 1 && $cy++;
$direction == 2 && $cx--;
$direction == 3 && $cy--;
if( $aux_matrix->[$cy][$cx] ) {
$direction = ++$direction % 4;
($cx, $cy) = ($cx_1, $cy_1);
}
else {
$aux_matrix->[$cy][$cx] = 1;
($cx_1, $cy_1) = ($cx, $cy);
push @result, $matrix[$cy-1][$cx-1];
$visits++;
}
}
return @result;
}
#------------------------------------------------------------------------------
1970;
|
