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| -rwxr-xr-x | challenge-345/jo-37/perl/ch-2.pl | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/challenge-345/jo-37/perl/ch-2.pl b/challenge-345/jo-37/perl/ch-2.pl new file mode 100755 index 0000000000..5f3db285a5 --- /dev/null +++ b/challenge-345/jo-37/perl/ch-2.pl @@ -0,0 +1,105 @@ +#!/usr/bin/perl + +use v5.26; +use Test2::V0 qw(!float -no_srand); +use Test2::Tools::Subtest 'subtest_streamed'; +use Getopt::Long; +use experimental 'signatures'; + +use PDL; +use PDL::NiceSlice; + + +### Options and Arguments + +my ($tests, $examples, $verbose); +GetOptions( + 'examples!' => \$examples, + 'tests!' => \$tests, + 'verbose!' => \$verbose, +) or usage(); + +run_tests($examples, $tests); # tests do not return + +usage() unless @ARGV; + +sub usage { + die <<~EOS; + $0 - last visitor + + usage: $0 [-examples] [-tests] [--] [N...] + + -examples + run the examples from the challenge + + -tests + run some tests + + N... + list of integers + + EOS +} + + +### Input and Output + +say last_visitor(@ARGV); + + +### Implementation +# +# For details see: +# https://github.sommrey.de/the-bears-den/2025/10/31/ch-345.html#task-2 + +sub last_visitor { + my $ints = long @_; + my $p = $ints >= 0; + my $seen = append $ints(-1:0)->where_both($p(-1:0)); + my $len = $p->cumusumover; + + $seen($p(*1)->enumvec + $len(-1) - $len)->(!$p;?); +} + + +### Examples and Tests + +sub run_tests ($examples, $tests) { + return unless $examples || $tests; + + state sub run_example ($args, $expected, $name, $reason=undef) { + my $result = last_visitor(@$args)->unpdl; + my $todo; + $todo = todo $reason if $reason; + is $result, $expected, + "$name: (@$args) -> (@$expected)"; + } + + plan 2; + + $examples ? subtest_streamed(examples => sub { + my @examples = ( + [[5, -1, -1], [5, -1], 'example 1'], + [[3, 7, -1, -1, -1], [7, 3, -1], 'example 2'], + [[2, -1, 4, -1, -1], [2, 4, 2], 'example 3'], + [[10, 20, -1, 30, -1, -1], [20, 30, 20], 'example 4'], + [[-1, -1, 5, -1], [-1, -1, 5], 'example 5'], + ); + plan scalar @examples; + run_example @$_ for @examples; + }) : pass 'skip examples'; + + $tests ? subtest_streamed(tests => sub { + my @tests = ( + [[-1, -1, -1], [-1, -1, -1], 'all -1'], + [[1, 2, 3], [], 'no -1'], + [[1, 0, 3, -1, -1], [3, 0], 'allow zero'], + [[1, 0, 3, -2, -3, -4, -5], [3, 0, 1, -5], + 'allow other negative numbers'], + ); + plan scalar @tests; + run_example @$_ for @tests; + }) : pass 'skip tests'; + + exit; +} |