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
|
#!/usr/bin/perl -s
use v5.16;
use Test2::V0;
use experimental qw(signatures);
use Syntax::Keyword::Gather;
our ($tests, $examples);
run_tests() if $tests || $examples; # does not return
die <<EOS unless @ARGV;
usage: $0 [-examples] [-tests] [N]
-examples
run the examples from the challenge
-tests
run some tests
N
generate hash-counting string of length N
EOS
### Input and Output
say hashcountingstring($ARGV[0]);
### Implementation
# Collect hash positions from end and insert hash signs.
sub hashcountingstring ($n) {
join('#', reverse gather {
take '';
for (; $n > 0; $n -= length($n) + 1) {
take $n x ($n > 1);
}
});
}
### Examples and tests
sub run_tests {
SKIP: {
skip "examples" unless $examples;
is hashcountingstring(1), '#', 'example a';
is hashcountingstring(2), '2#', 'example b';
is hashcountingstring(3), '#3#', 'example c';
is hashcountingstring(10), '#3#5#7#10#', 'example d';
is hashcountingstring(14), '2#4#6#8#11#14#', 'example e';
}
SKIP: {
skip "tests" unless $tests;
is hashcountingstring(11), '2#4#6#8#11#', '11';
is hashcountingstring(12), '#3#5#7#9#12#', '12';
is hashcountingstring(13), '#3#5#7#10#13#', '13';
}
done_testing;
exit;
}
|
