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#!/usr/bin/perl -w |
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|
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# symmetry.pl |
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# |
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# 08/26/07 02:40:37 CEST Dobrica Pavlinusic <dpavlin@rot13.org> |
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|
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use strict; |
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|
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my $board = << '_BOARD_'; |
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+-+-+-+-+-+-+-+-+ |
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| | |o| | | |
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+ + +-+ +-+ | |
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|o| | o | o | |
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+ + +-+ +-+ | |
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| | o | | | |
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+-+-+ +-+-+-+-+ |
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| | |o| | |
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+-+ + +-+-+ +-+ |
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| |o| |o|o|o|o| |
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+ + +-+-+-+-+ +-+ |
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|o| | | | |
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+ +-+-+-+-+-+-+-+ |
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| | o | |
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+-+-+-+-+-+-+-+-+ |
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| o | o | |
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+-+-+-+-+-+-+-+-+ |
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_BOARD_ |
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|
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my $debug = shift @ARGV || 0; |
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|
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my @board = map { split(//) } split(/\n/, $board); |
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my @trace; |
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|
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# line length |
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my $ll = 8 * 2 + 1; |
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|
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my @step_name = ( qw/right down left up/ ); |
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my @move_by = ( 1, $ll, -1, -$ll ); |
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my $step = 0; # right |
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|
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# offset 0, top-left corner |
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my $pos = 0; |
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|
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# unknown trace position |
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my $unknown = ' '; |
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|
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# path traversed |
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my @directions; |
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|
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my @shapes_found; |
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|
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my @shapes_start = ( '0,0' ); #( qw/0,0 1,0 0,3/ ); |
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|
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sub draw { |
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my $o = 0; |
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my $out; |
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while ( $o < $#board ) { |
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$out .= join('', @board[ $o .. $o + $ll - 1 ]); |
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$out .= ' '; |
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$out .= join('', @trace[ $o .. $o + $ll - 1 ]); |
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$out .= "\n"; |
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$o += $ll; |
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} |
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return $out; |
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} |
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|
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sub trace { |
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warn "## trace $pos\n"; |
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$trace[ $pos ] = $board[ $pos ]; |
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} |
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|
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my ( $tr_x, $tr_y ); |
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|
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sub pos_x_y { |
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my $y = int($pos / ($ll*2)); |
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my $x = int(($pos % $ll) / 2); |
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|
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$tr_x = $x unless defined $tr_x; |
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$tr_y = $y unless defined $tr_y; |
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|
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$tr_x = $x if $x > $tr_x && $y == $tr_y; |
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$tr_y = $y if $y < $tr_y && $x == $tr_x; |
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|
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warn "## pos_x_y $pos -> $x,$y\n"; |
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|
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return ($x,$y) if wantarray; |
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return "$x,$y"; |
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} |
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|
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sub move { |
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$pos += $move_by[ $step ]; |
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trace; |
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$pos += $move_by[ $step ]; |
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trace; |
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push @directions, $step; |
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warn "move $step $step_name[$step] to ", scalar pos_x_y, "\n"; |
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} |
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|
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sub follow { |
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$step = shift; |
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$step %= 4; |
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warn "follow $step $step_name[$step]\n"; |
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} |
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|
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my $ok_path = qr/[\|\-]/; |
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|
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sub can_turn { |
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my $try_step = shift; |
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die "no step?" unless defined $try_step; |
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|
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$try_step %= 4; |
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|
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my $turn_pos = $pos + $move_by[$try_step]; |
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|
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my $old = $trace[ $turn_pos ]; |
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$trace[ $turn_pos ] = '?'; |
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warn "TEST\n",draw( @trace ); |
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$trace[ $turn_pos ] = $old; |
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|
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if ( $board[ $turn_pos ] =~ $ok_path ) { |
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warn "OK can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n"; |
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$step = $try_step; |
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return 1; |
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} else { |
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warn "NOPE can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n"; |
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return 0; |
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} |
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} |
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|
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sub show_directions { |
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return |
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join('', |
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map { |
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substr($step_name[$_],0,1) |
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} @directions |
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) |
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; |
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} |
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|
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sub shape { |
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|
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my ($x,$y) = @_; |
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|
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$pos = $y * $ll * 2 + $x * 2; |
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|
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warn "<<< shape from $x,$y pos: $pos\n"; |
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@trace = ($unknown) x ( $#board + 1 ); |
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@directions = (); |
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trace; |
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|
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my $len = 0; |
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|
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while( 1 ) { |
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|
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my $next_pos = $pos + $move_by[ $step ]; |
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warn "# pos: $pos next_pos: $next_pos step: $step $step_name[$step] trace: ",show_directions,"\n"; |
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|
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if ( $trace[ $next_pos ] ne $unknown ) { |
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warn "position $next_pos re-visited, exiting\n"; |
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last; |
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} elsif ( $board[ $next_pos ] =~ $ok_path ) { |
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warn "OK next_pos = $next_pos b($board[$next_pos]) t($trace[$next_pos])\n"; |
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move; |
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$len++; |
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can_turn( $step + 1 ); |
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} else { |
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warn "find line continuation from $step $step_name[$step]...\n"; |
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can_turn( $step - 1 ) || can_turn( $step + 1 ) || die "can't find new direction"; |
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} |
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warn draw( @trace ); |
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|
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if ( $debug ) { |
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warn "## tr: $tr_x,$tr_y\n"; |
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print "WAIT> press enter | ",show_directions; my $foo = <STDIN>; |
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} |
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} |
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|
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push @shapes_found, { x => $x, y => $y, len => $len, directions => show_directions }; |
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|
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warn ">>> ended at $pos, line length: $len, directions traversed: ",show_directions,"\n"; |
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|
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my $tr = "$tr_x,$tr_y"; |
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if ( ! grep( /\Q$tr\E/, @shapes_start ) && $tr_x < 8 ) { |
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print "INFO: added top-right $tr\n"; |
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push @shapes_start, $tr; |
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} |
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|
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print "WAIT> press enter"; my $foo = <STDIN>; |
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|
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return $len; |
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} |
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|
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foreach my $start ( @shapes_start ) { |
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my $len = shape( split(/,/,$start) ); |
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warn "## $start has $len elements\n"; |
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} |
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|
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print ">>> RESULTS:\n"; |
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foreach my $r ( @shapes_found ) { |
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printf "%2d,%-2d len: %-4d directions: %s\n", $r->{x}, $r->{y}, $r->{len}, $r->{directions}; |
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} |
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