From bc069894f3a3cad374447d1d15fb296b67030757 Mon Sep 17 00:00:00 2001
From: "Gustavo L. de M. Chaves" <gustavo@cpqd.com.br>
Date: Tue, 21 May 2019 15:17:00 -0300
Subject: Gustavo Chaves Perl 5 solutions to Challenge 009

---
 challenge-009/gustavo-chaves/perl5/README.pod | 45 +++++++++++++++++++++++++++
 challenge-009/gustavo-chaves/perl5/ch-1.pl    | 15 +++++++++
 challenge-009/gustavo-chaves/perl5/ch-2.pl    | 41 ++++++++++++++++++++++++
 3 files changed, 101 insertions(+)
 create mode 100644 challenge-009/gustavo-chaves/perl5/README.pod
 create mode 100755 challenge-009/gustavo-chaves/perl5/ch-1.pl
 create mode 100755 challenge-009/gustavo-chaves/perl5/ch-2.pl

diff --git a/challenge-009/gustavo-chaves/perl5/README.pod b/challenge-009/gustavo-chaves/perl5/README.pod
new file mode 100644
index 0000000000..cba7c00185
--- /dev/null
+++ b/challenge-009/gustavo-chaves/perl5/README.pod
@@ -0,0 +1,45 @@
+=pod
+
+=encoding utf8
+
+=head1 #1 First square with five distinct digits
+
+=over 4
+
+Write a script that finds the first square number that has at least 5 distinct
+digits. This was proposed by Laurent Rosenfeld.
+
+=back
+
+This is easily solvable by splitting the square digits and tucking them in a
+hash to drop duplicates. Then we only have to see if there are five keys in the
+hash.
+
+=head1 #2 Ranking
+
+=over 4
+
+Write a script to perform different types of ranking as described below:
+
+=over 4
+
+=item 1. Standard Ranking (1224): Items that compare equal receive the same ranking number, and then a gap is left in the ranking numbers.
+=item 2. Modified Ranking (1334): It is done by leaving the gaps in the ranking numbers before the sets of equal-ranking items.
+=item 3. Dense Ranking    (1223): Items that compare equally receive the same ranking number, and the next item(s) receive the immediately following ranking number.
+
+=back
+
+For more information, please refer to L<wiki page|https://en.wikipedia.org/wiki/Ranking>.
+
+=back
+
+This problem isn't very well defined because one doesn't know which type of
+items should being ranked. Numbers, strings, generic objects?
+
+I'm assuming that we're ranking numbers which are passed as command line
+arguments to the script. Like this:
+
+    $ ./ch-2.pl 8 4 2 4 4 3 3 4 5 7 8 6 5 3 2 1 3
+    Standard Ranking: 1 2 2 4 4 4 4 8 8 8 8 12 12 14 15 16 16
+    Modified Ranking: 1 3 3 7 7 7 7 11 11 11 11 13 13 14 15 17 17
+       Dense Ranking: 1 2 2 3 3 3 3 4 4 4 4 5 5 6 7 8 8
diff --git a/challenge-009/gustavo-chaves/perl5/ch-1.pl b/challenge-009/gustavo-chaves/perl5/ch-1.pl
new file mode 100755
index 0000000000..9decc20082
--- /dev/null
+++ b/challenge-009/gustavo-chaves/perl5/ch-1.pl
@@ -0,0 +1,15 @@
+#!/usr/bin/env perl
+
+use 5.026;
+use strict;
+use autodie;
+use warnings;
+
+my ($i, $square, %digits);
+
+for ($i = 0; 5 != scalar keys %digits; ++$i) {
+    $square = $i * $i;
+    %digits = map {$_ => undef} split //, $square;
+}
+
+say "$i^2 == $square";
diff --git a/challenge-009/gustavo-chaves/perl5/ch-2.pl b/challenge-009/gustavo-chaves/perl5/ch-2.pl
new file mode 100755
index 0000000000..f03817963a
--- /dev/null
+++ b/challenge-009/gustavo-chaves/perl5/ch-2.pl
@@ -0,0 +1,41 @@
+#!/usr/bin/env perl
+
+use 5.026;
+use strict;
+use autodie;
+use warnings;
+
+# @ARGV should contain a list of numbers which I'll rank by magnitude.
+
+# First I'll use a hash to count how many times each numbers occurs in @ARGV.
+
+my %item_count;
+++$item_count{$_} foreach @ARGV;
+
+my @sorted_keys = sort {$a <=> $b} keys %item_count;
+
+my $i;
+
+print "Standard Ranking:";
+$i = 1;
+foreach my $key (@sorted_keys) {
+    print " $i" x $item_count{$key};
+    $i += $item_count{$key};
+}
+print "\n";
+
+print "Modified Ranking:";
+$i = 0;
+foreach my $key (@sorted_keys) {
+    $i += $item_count{$key};
+    print " $i" x $item_count{$key};
+}
+print "\n";
+
+print "   Dense Ranking:";
+$i = 1;
+foreach my $key (@sorted_keys) {
+    print " $i" x $item_count{$key};
+    $i += 1;
+}
+print "\n";
-- 
cgit