1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
#!/usr/bin/perl -w
# Copyright 2010, 2011 Kevin Ryde
# This file is part of Math-PlanePath.
#
# Math-PlanePath is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
#
# Math-PlanePath is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>.
use 5.010;
use strict;
use warnings;
use Smart::Comments;
{
my $x = 2;
my $y = 0;
### initial: "$x,$y"
foreach (1 .. 6) {
# ($x,$y) = (($x+3*$y)/-2, # 120
# ($x-$y)/2);
# ($x,$y) = ((3*$y-$x)/2, # 2x120
# ($x+$y)/-2);
# ($x,$y) = (($x-3*$y)/2, # 60
# ($x+$y)/2);
($x,$y) = (($x+3*$y)/2, # -60
($y-$x)/2);
### to: "$x,$y"
}
exit 0;
}
{
my @seen;
foreach my $x (2 .. 20) {
my $ylimit = $x/3;
for (my $y = ($x&1); $y <= $ylimit; $y+=2) {
my $h = 3*$y*$y + $x*$x;
if ($seen[$h]) {
print "duplicate $x,$y: $seen[$h]\n";
} else {
$seen[$h] = "$x,$y";
}
}
}
my @hypots = map {defined $seen[$_] ? $_ : ()} 0 .. $#seen;
@hypots = sort {$a<=>$b} @hypots;
$,=',';
print @hypots,"\n";
exit 0;
}
|
