# Return the list of dead cells surrounding a cell sub get_dead_cells { my ( $cells, $x0, $y0 ) = ( shift->{Cells}, @_ ); my ( $x1, $x2, $y1, $y2 ) = ( $x0 - 1, $x0 + 1, $y0 - 1, $y0 + 1 ); ( ( "$x1:$y1" ) x !( 0 + exists $cells->{ "$x1:$y1" } ), ( "$x1:$y0" ) x !( 0 + exists $cells->{ "$x1:$y0" } ), ( "$x1:$y2" ) x !( 0 + exists $cells->{ "$x1:$y2" } ), ( "$x0:$y1" ) x !( 0 + exists $cells->{ "$x0:$y1" } ), ( "$x0:$y2" ) x !( 0 + exists $cells->{ "$x0:$y2" } ), ( "$x2:$y1" ) x !( 0 + exists $cells->{ "$x2:$y1" } ), ( "$x2:$y0" ) x !( 0 + exists $cells->{ "$x2:$y0" } ), ( "$x2:$y2" ) x !( 0 + exists $cells->{ "$x2:$y2" } ) ); } sub get_num_live { my ( $cells, $x0, $y0 ) = ( shift->{Cells}, @_ ); my ( $x1, $x2, $y1, $y2 ) = ( $x0 - 1, $x0 + 1, $y0 - 1, $y0 + 1 ); ( 0 + exists $cells->{ "$x1:$y1" } ) + ( 0 + exists $cells->{ "$x1:$y0" } ) + ( 0 + exists $cells->{ "$x1:$y2" } ) + ( 0 + exists $cells->{ "$x0:$y1" } ) + ( 0 + exists $cells->{ "$x0:$y2" } ) + ( 0 + exists $cells->{ "$x2:$y1" } ) + ( 0 + exists $cells->{ "$x2:$y0" } ) + ( 0 + exists $cells->{ "$x2:$y2" } ); }