viewvc.cgi/symmetry-circle/symmetry.pl

#!/usr/bin/perl -w

# symmetry.pl
#
# 08/26/07 02:40:37 CEST Dobrica Pavlinusic <dpavlin@rot13.org>

use strict;

my $board = << '_BOARD_';
+-+-+-+-+-+-+-+-+
| |   |o| |     |
+ +   +-+ +-+   |
|o|   |  o  | o |
+ +   +-+ +-+   |
| |  o  | |     |
+-+-+   +-+-+-+-+
|   |   |o|     |
+-+ +   +-+-+ +-+
| |o|   |o|o|o|o|
+ + +-+-+-+-+ +-+
|o|   |   |     |
+ +-+-+-+-+-+-+-+
| |      o      |
+-+-+-+-+-+-+-+-+
|    o    |  o  |
+-+-+-+-+-+-+-+-+
_BOARD_

my $debug = shift @ARGV || 0;

my @board = map { split(//) } split(/\n/, $board);
my @trace;
my @visited = (' ') x ($#board + 1);

# line length
my $ll = 8 * 2 + 1;

my @step_name = ( qw/right down left up/ );
my @move_by = ( 1, $ll, -1, -$ll );
my $step = 0;   # right

# offset 0, top-left corner
my $pos = 0;

# unknown trace position
my $unknown = ' ';

# path traversed
my @directions;

my @shapes_found;

my @shapes_start = ( '0,0' ); #( qw/0,0 1,0 0,3/ );

sub draw {
        my $o = 0;
        my $out = "\n  " . join('',
                ('0 1 2 3 4 5 6 7 8 | ') x 3
        ) . "\n";
        while ( $o < $#board ) {
                my $l = '|';
                if ( $o % ($ll*2) == 0) {
                        my $y = int($o / ($ll*2));
                        $out .= "$y ";
                        $l = $y;
                } else {
                        $out .= "  ";
                }

                $out .= join('', @board[ $o .. $o + $ll - 1 ]);
                $out .= " $l ";
                $out .= join('', @trace[ $o .. $o + $ll - 1 ]);
                $out .= " $l ";
                $out .= join('', @visited[ $o .. $o + $ll - 1 ]);
                $out .= " $l\n";
                $o += $ll;
        }

        $out .= "\n";

        return $out;
}

sub trace {
        warn "## trace $pos\n";
        $trace[ $pos ] = $board[ $pos ];
        $visited[$pos]++;
}

my ( $tr_x, $tr_y );
my ( $bl_x, $bl_y );

sub x_y {
        my $p = shift;

        my $update = 0;
        if ( ! defined( $p ) ) {
                $p = $pos;
                $update = 1;
        }

        my $y = int($p / ($ll*2));
        my $x = int(($p % $ll) / 2);

        warn "??? x_y($p) $x,$y tr: $tr_x,$tr_y bl: $bl_x,$bl_y\n";

        if ( $update ) {

#               $tr_x = $x if $x > $tr_x && $y == $tr_y;
#               $tr_y = $y if $y < $tr_y && $x == $tr_x;

                if (
                        $y < $tr_y
                        ||
                        $y <= $tr_y && $x > $tr_x
                ) {
                        ( $tr_x, $tr_y ) = ( $x, $y );
                        warn "## UPDATED tr: $tr_x,$tr_y\n";
                }

                if (
                        $x < $bl_x
                        ||
                        $y > $bl_y
                ) {
                        ( $bl_x, $bl_y ) = ( $x, $y );
                        warn "## UPDATED bl: $bl_x,$bl_y\n";
                }

#               $bl_x = $x if $x < $bl_x; # && $y == $bl_y;
#               $bl_y = $y if $y > $bl_y; # && $x == $bl_x;
        
        }

        warn "## x_y($p) -> $x,$y ",
                $update ? " tr: $tr_x,$tr_y bl: $bl_x,$bl_y" : '',
                "\n";

#       return ($x,$y) if wantarray;
        return "$x,$y";
}

sub move {
        $pos += $move_by[ $step ];
        trace;
        $pos += $move_by[ $step ];
        trace;
        push @directions, $step;
        warn "move $step $step_name[$step] to ", x_y, "\n";
}

sub follow {
        $step = shift;
        $step %= 4;
        warn "follow $step $step_name[$step]\n";
}

my $ok_path = qr/[\|\-]/;

sub can_turn {
        my $try_step = shift;
        die "no step?" unless defined $try_step;

        $try_step %= 4;

        my $turn_pos = $pos + $move_by[$try_step];

        my $old = $trace[ $turn_pos ];
        $trace[ $turn_pos ] = '?';
        $trace[ $pos ] = '*';
        warn "TEST ", x_y($turn_pos), "\n",draw;
        $trace[ $turn_pos ] = $old;

        if ( $board[ $turn_pos ] =~ $ok_path ) {
                warn "OK can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n";
                $step = $try_step;
                return 1;
        } else {
                warn "NOPE can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n";
                return 0;
        }
}

sub show_directions {
        return 
                join('',
                        map {
                                substr($step_name[$_],0,1)
                        } @directions
                )
        ;
}

sub shape {

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

        $pos = $y * $ll * 2 + $x * 2;

        @trace = ($unknown) x ( $#board + 1 );
        @directions = ();
        trace;

        my $len = 0;
        ( $tr_x, $tr_y ) = ( $x,$y );
        ( $bl_x, $bl_y ) = ( $x,$y );
        $step = 0;

        if ( $visited[$pos] > 3 ) {
                warn "*** shape from $x,$y pos: $pos iterated 4 times, skipping\n";
                return;
        }

        warn "<<< shape from $x,$y pos: $pos\n";

        while( 1 ) {

                my $next_pos = $pos + $move_by[ $step ];
                warn "# pos: $pos next_pos: $next_pos step: $step $step_name[$step] trace: ",show_directions,"\n";

                if ( $trace[ $next_pos ] ne $unknown ) {
                        warn "position $next_pos re-visited, exiting\n";
                        last;
                } elsif ( $board[ $next_pos ] =~ $ok_path ) {
                        warn "OK next_pos = $next_pos b($board[$next_pos]) t($trace[$next_pos])\n";
                        move;
                        $len++;
                        can_turn( $step + 1 );
                } else {
                        warn "find line continuation from $step $step_name[$step]...\n";
                        can_turn( $step - 1 ) || can_turn( $step + 1 ) || die "can't find new direction";
                }
                warn draw;

                warn "## tr: $tr_x,$tr_y bl: $bl_x,$bl_y\n";

                if ( $debug ) {
                        print "WAIT> press enter | ",show_directions; my $foo = <STDIN>;
                }
        }

        push @shapes_found, { x => $x, y => $y, len => $len, directions => show_directions };

        my $tr = "$tr_x,$tr_y";
        my $bl = "$bl_x,$bl_y";

        warn ">>> ended at $pos, line length: $len, directions traversed: ",show_directions," tr: $tr bl: $bl\n";

        if ( ! grep( /\Q$tr\E/, @shapes_start ) && $tr_x < 8 ) {
                warn "INFO: added $tr top-right\n";
                push @shapes_start, $tr;
        }
        if ( ! grep( /\Q$bl\E/, @shapes_start ) && $bl_y < 8 ) {
                warn "INFO: added $bl bottom-left\n";
                push @shapes_start, $bl;
        }

        print "WAIT> press enter"; my $foo = <STDIN>;

        return $len;
}

foreach my $start ( @shapes_start ) {
        my $len = shape( split(/,/,$start) );
        warn "## $start has $len elements\n";
}

print ">>> RESULTS:\n";
foreach my $r ( @shapes_found ) {
        printf "%2d,%-2d len: %-4d directions: %s\n", $r->{x}, $r->{y}, $r->{len}, $r->{directions};
}
1	dpavlin	1	#!/usr/bin/perl -w
2
3			# symmetry.pl
4			#
5			# 08/26/07 02:40:37 CEST Dobrica Pavlinusic <dpavlin@rot13.org>
6
7			use strict;
8
9			my $board = << '_BOARD_';
10			+-+-+-+-+-+-+-+-+
11			\| \| \|o\| \| \|
12			+ + +-+ +-+ \|
13			\|o\| \| o \| o \|
14			+ + +-+ +-+ \|
15			\| \| o \| \| \|
16			+-+-+ +-+-+-+-+
17			\| \| \|o\| \|
18			+-+ + +-+-+ +-+
19			\| \|o\| \|o\|o\|o\|o\|
20			+ + +-+-+-+-+ +-+
21			\|o\| \| \| \|
22			+ +-+-+-+-+-+-+-+
23			\| \| o \|
24			+-+-+-+-+-+-+-+-+
25			\| o \| o \|
26			+-+-+-+-+-+-+-+-+
27			_BOARD_
28
29	dpavlin	4	my $debug = shift @ARGV \|\| 0;
30
31	dpavlin	1	my @board = map { split(//) } split(/\n/, $board);
32	dpavlin	3	my @trace;
33	dpavlin	6	my @visited = (' ') x ($#board + 1);
34	dpavlin	1
35			# line length
36			my $ll = 8 * 2 + 1;
37
38	dpavlin	3	my @step_name = ( qw/right down left up/ );
39			my @move_by = ( 1, $ll, -1, -$ll );
40			my $step = 0; # right
41
42			# offset 0, top-left corner
43			my $pos = 0;
44
45			# unknown trace position
46			my $unknown = ' ';
47
48	dpavlin	4	# path traversed
49			my @directions;
50
51	dpavlin	5	my @shapes_found;
52	dpavlin	4
53	dpavlin	5	my @shapes_start = ( '0,0' ); #( qw/0,0 1,0 0,3/ );
54
55	dpavlin	1	sub draw {
56			my $o = 0;
57	dpavlin	6	my $out = "\n " . join('',
58			('0 1 2 3 4 5 6 7 8 \| ') x 3
59			) . "\n";
60	dpavlin	1	while ( $o < $#board ) {
61	dpavlin	6	my $l = '\|';
62			if ( $o % ($ll*2) == 0) {
63			my $y = int($o / ($ll*2));
64			$out .= "$y ";
65			$l = $y;
66			} else {
67			$out .= " ";
68			}
69
70	dpavlin	3	$out .= join('', @board[ $o .. $o + $ll - 1 ]);
71	dpavlin	6	$out .= " $l ";
72	dpavlin	3	$out .= join('', @trace[ $o .. $o + $ll - 1 ]);
73	dpavlin	6	$out .= " $l ";
74			$out .= join('', @visited[ $o .. $o + $ll - 1 ]);
75			$out .= " $l\n";
76	dpavlin	1	$o += $ll;
77			}
78	dpavlin	6
79			$out .= "\n";
80
81	dpavlin	1	return $out;
82			}
83
84			sub trace {
85	dpavlin	3	warn "## trace $pos\n";
86	dpavlin	1	$trace[ $pos ] = $board[ $pos ];
87	dpavlin	6	$visited[$pos]++;
88	dpavlin	1	}
89
90	dpavlin	5	my ( $tr_x, $tr_y );
91	dpavlin	6	my ( $bl_x, $bl_y );
92	dpavlin	5
93	dpavlin	6	sub x_y {
94			my $p = shift;
95	dpavlin	5
96	dpavlin	6	my $update = 0;
97			if ( ! defined( $p ) ) {
98			$p = $pos;
99			$update = 1;
100			}
101	dpavlin	5
102	dpavlin	6	my $y = int($p / ($ll*2));
103			my $x = int(($p % $ll) / 2);
104	dpavlin	5
105	dpavlin	6	warn "??? x_y($p) $x,$y tr: $tr_x,$tr_y bl: $bl_x,$bl_y\n";
106	dpavlin	5
107	dpavlin	6	if ( $update ) {
108
109			# $tr_x = $x if $x > $tr_x && $y == $tr_y;
110			# $tr_y = $y if $y < $tr_y && $x == $tr_x;
111
112			if (
113			$y < $tr_y
114			\|\|
115			$y <= $tr_y && $x > $tr_x
116			) {
117			( $tr_x, $tr_y ) = ( $x, $y );
118			warn "## UPDATED tr: $tr_x,$tr_y\n";
119			}
120
121			if (
122			$x < $bl_x
123			\|\|
124			$y > $bl_y
125			) {
126			( $bl_x, $bl_y ) = ( $x, $y );
127			warn "## UPDATED bl: $bl_x,$bl_y\n";
128			}
129
130			# $bl_x = $x if $x < $bl_x; # && $y == $bl_y;
131			# $bl_y = $y if $y > $bl_y; # && $x == $bl_x;
132
133			}
134
135			warn "## x_y($p) -> $x,$y ",
136			$update ? " tr: $tr_x,$tr_y bl: $bl_x,$bl_y" : '',
137			"\n";
138
139			# return ($x,$y) if wantarray;
140	dpavlin	5	return "$x,$y";
141			}
142
143	dpavlin	1	sub move {
144			$pos += $move_by[ $step ];
145			trace;
146			$pos += $move_by[ $step ];
147			trace;
148	dpavlin	4	push @directions, $step;
149	dpavlin	6	warn "move $step $step_name[$step] to ", x_y, "\n";
150	dpavlin	1	}
151
152			sub follow {
153			$step = shift;
154			$step %= 4;
155			warn "follow $step $step_name[$step]\n";
156			}
157
158			my $ok_path = qr/[\\|\-]/;
159
160			sub can_turn {
161	dpavlin	2	my $try_step = shift;
162			die "no step?" unless defined $try_step;
163	dpavlin	1
164	dpavlin	2	$try_step %= 4;
165	dpavlin	1
166	dpavlin	2	my $turn_pos = $pos + $move_by[$try_step];
167
168	dpavlin	1	my $old = $trace[ $turn_pos ];
169			$trace[ $turn_pos ] = '?';
170	dpavlin	6	$trace[ $pos ] = '*';
171			warn "TEST ", x_y($turn_pos), "\n",draw;
172	dpavlin	1	$trace[ $turn_pos ] = $old;
173
174			if ( $board[ $turn_pos ] =~ $ok_path ) {
175	dpavlin	5	warn "OK can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n";
176	dpavlin	2	$step = $try_step;
177	dpavlin	1	return 1;
178			} else {
179	dpavlin	5	warn "NOPE can_turn $try_step $step_name[$try_step] turn_pos = $turn_pos b($board[$turn_pos]) t($trace[$turn_pos])\n";
180	dpavlin	1	return 0;
181			}
182			}
183
184	dpavlin	4	sub show_directions {
185			return
186			join('',
187			map {
188			substr($step_name[$_],0,1)
189			} @directions
190			)
191			;
192			}
193
194	dpavlin	3	sub shape {
195	dpavlin	1
196	dpavlin	3	my ($x,$y) = @_;
197	dpavlin	1
198	dpavlin	3	$pos = $y * $ll * 2 + $x * 2;
199
200			@trace = ($unknown) x ( $#board + 1 );
201	dpavlin	4	@directions = ();
202	dpavlin	3	trace;
203
204			my $len = 0;
205	dpavlin	6	( $tr_x, $tr_y ) = ( $x,$y );
206			( $bl_x, $bl_y ) = ( $x,$y );
207			$step = 0;
208	dpavlin	3
209	dpavlin	6	if ( $visited[$pos] > 3 ) {
210			warn "*** shape from $x,$y pos: $pos iterated 4 times, skipping\n";
211			return;
212			}
213
214			warn "<<< shape from $x,$y pos: $pos\n";
215
216	dpavlin	3	while( 1 ) {
217
218			my $next_pos = $pos + $move_by[ $step ];
219	dpavlin	4	warn "# pos: $pos next_pos: $next_pos step: $step $step_name[$step] trace: ",show_directions,"\n";
220	dpavlin	3
221			if ( $trace[ $next_pos ] ne $unknown ) {
222			warn "position $next_pos re-visited, exiting\n";
223			last;
224			} elsif ( $board[ $next_pos ] =~ $ok_path ) {
225			warn "OK next_pos = $next_pos b($board[$next_pos]) t($trace[$next_pos])\n";
226			move;
227			$len++;
228			can_turn( $step + 1 );
229			} else {
230			warn "find line continuation from $step $step_name[$step]...\n";
231			can_turn( $step - 1 ) \|\| can_turn( $step + 1 ) \|\| die "can't find new direction";
232			}
233	dpavlin	6	warn draw;
234	dpavlin	3
235	dpavlin	6	warn "## tr: $tr_x,$tr_y bl: $bl_x,$bl_y\n";
236
237	dpavlin	4	if ( $debug ) {
238			print "WAIT> press enter \| ",show_directions; my $foo = <STDIN>;
239			}
240	dpavlin	1	}
241
242	dpavlin	5	push @shapes_found, { x => $x, y => $y, len => $len, directions => show_directions };
243	dpavlin	4
244	dpavlin	6	my $tr = "$tr_x,$tr_y";
245			my $bl = "$bl_x,$bl_y";
246	dpavlin	5
247	dpavlin	6	warn ">>> ended at $pos, line length: $len, directions traversed: ",show_directions," tr: $tr bl: $bl\n";
248
249	dpavlin	5	if ( ! grep( /\Q$tr\E/, @shapes_start ) && $tr_x < 8 ) {
250	dpavlin	6	warn "INFO: added $tr top-right\n";
251	dpavlin	5	push @shapes_start, $tr;
252			}
253	dpavlin	6	if ( ! grep( /\Q$bl\E/, @shapes_start ) && $bl_y < 8 ) {
254			warn "INFO: added $bl bottom-left\n";
255			push @shapes_start, $bl;
256			}
257	dpavlin	5
258	dpavlin	4	print "WAIT> press enter"; my $foo = <STDIN>;
259
260	dpavlin	3	return $len;
261	dpavlin	1	}
262
263	dpavlin	5	foreach my $start ( @shapes_start ) {
264	dpavlin	3	my $len = shape( split(/,/,$start) );
265			warn "## $start has $len elements\n";
266			}
267	dpavlin	4
268			print ">>> RESULTS:\n";
269	dpavlin	5	foreach my $r ( @shapes_found ) {
270	dpavlin	4	printf "%2d,%-2d len: %-4d directions: %s\n", $r->{x}, $r->{y}, $r->{len}, $r->{directions};
271			}