# 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" } ); }