oldtechaa

First of all, a greeting. I posted an introduction with a notification of intent to take over a module on CPAN, but the maintainer responded to me. I'm Avery, I'm developing SeekMIDI, a small graphical MIDI sequencer. I started it in 2016 and I took a long break from programming entirely, and I've just restarted developing my programming skills again. For starters, I'm working on Perl Weekly Challenges and bug fixes to modules.

Without further ado, here are my solutions to the PWC #208. All solutions are about to be posted, but this could be a spoiler if you're trying to solve it too. I was very pleased this week that I got it down to about 15-25 minutes for each task, so I'm definitely getting more comfortable in Perl again.

First, task 1:

use strict;
use v5.10;

my @list1 = ("Perl", "Raku", "Love");
my @list2 = ("Raku", "Perl", "Hate");

# my @list1 = ("A", "B", "C");
# my @list2 = ("D", "E", "F");

# my @list1 = ("A", "B", "C");
# my @list2 = ("C", "A", "B");

my $minindex;
my @results;
for (my $index1 = 0; $index1 < scalar @list1; $index1++) {
    for (my $index2 = 0; $index2 < scalar @list2; $index2++) {
        if ($list1[$index1] eq $list2[$index2] && defined($minindex)) {
            if ($index1 + $index2 < $minindex) {
                @results = ($list1[$index1]);
                $minindex = $index1 + $index2;
            } elsif ($index1 + $index2 == $minindex) {
                push (@results, $list1[$index1]);
            }
        } elsif ($list1[$index1] eq $list2[$index2] && !defined($minindex)) {
            @results = ($list1[$index1]);
            $minindex = $index1 + $index2;
        }
    }
}
if (scalar @results == 0) {exit}
foreach (@results) {
    say $_;
}

Pretty simple. For every item in list 1, I iterate through list 2 and look for a match with a lower sum than the previous lowest sum. If I find one it replaces the previous results, if it's equal I add it to the results. Then I say the results.

Now task 2:

use strict;
use v5.10;

my $index;
my ($duplicate, $missing);
foreach (@ARGV) {
    if (!defined($index)) {$index = 1 and next}
    if ($_ == $ARGV[$index - 1]) {$duplicate = $_}
    if ($_ != $ARGV[$index - 1] + 1) {$missing = $ARGV[$index - 1] + 1}
    $index++;
}
defined($duplicate) && defined($missing) ? say ("Duplicate is $duplicate", "\n", "Missing is $missing") : say -1;

For this one, I iterate through them and if it's the same thing as the previous one it's my duplicate and if it's not the previous item plus 1 then it's your missing number.

Anyways, hope you liked them this week. I always look at the other solutions blogged about and get ideas for use in my code. If you have any better ideas comment below.