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
|
#!/usr/bin/env perl
use strict;
use warnings;
use experimental qw{ say postderef signatures state };
my @examples = (
[ 1, 2, 3, 4 ],
[ 2, 4, 6, 8, 9, 10, 11 ],
[2],
);
for my $e (@examples) {
my @out = arithmatic_slices( $e->@* );
my $out = join ', ', map { "($_)" } map { join ',', $_->@* } @out;
my $in = join ',', $e->@*;
say <<"END";
Input: \@array = ($in)
Output: ($out)
END
}
sub arithmatic_slices ( @array ) {
return () if scalar @array < 3;
my @output;
my $max = -1 + scalar @array;
OUTER: for my $i ( 0 .. $max - 1) {
my $diff = abs( $array[$i] - $array[ $i + 1 ] );
my @slice;
push @slice, $array[$i];
for my $j ( $i + 1 .. $max ) {
my $ldiff = abs( $array[$j] - $array[ $j - 1 ] );
if ( $ldiff == $diff ) {
push @slice, $array[$j];
my @copy = @slice;
push @output, \@copy if scalar @slice > 2;
}
else {
next OUTER;
}
}
}
# first sort makes the arrays numerically sorted by first value
# second sort makes the arrays sorted by length
@output = sort { scalar $a->@* <=> scalar $b->@* }
sort { $a->[0] <=> $b->[0] } @output;
return @output;
}
|
