Merge pull request #9151 from pjcs00/wk245

Week 245

3 files changed, 94 insertions, 0 deletions

diff --git a/challenge-245/peter-campbell-smith/blog.txt b/challenge-245/peter-campbell-smith/blog.txt
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+++ b/challenge-245/peter-campbell-smith/blog.txt
@@ -0,0 +1 @@
+http://ccgi.campbellsmiths.force9.co.uk/challenge/245
diff --git a/challenge-245/peter-campbell-smith/perl/ch-1.pl b/challenge-245/peter-campbell-smith/perl/ch-1.pl
new file mode 100755
index 0000000000..6cad9a701d
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+++ b/challenge-245/peter-campbell-smith/perl/ch-1.pl
@@ -0,0 +1,24 @@
+#!/usr/bin/perl
+
+use v5.26;    # The Weekly Challenge - 2023-11-27
+use utf8;     # Week 245 task 1 - Sort language
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+sort_language(['perl', 'c', 'python'], [2, 1, 3]);
+sort_language(['perl', 'fortran', 'algol', 'pascal', 'html', 'apl', 'c++', 'French'],
+	[7, 3, 5, 1, 8, 2, 4, 6]);
+	
+sub sort_language {
+	
+	my (@languages, @ranks, @order);
+	
+	@languages = @{$_[0]};
+	@ranks = @{$_[1]};
+	
+	$order[$ranks[$_] - 1] = $languages[$_] for 0 .. @languages - 1;
+	
+	say qq[\nInput:      \@lang = ('] . join(q[', '], @languages) . q[')];
+	say qq[      \@popularity = (] . join(', ', @ranks) . ')';
+	say qq[Output:             ('] . join(q[', '], @order) . q[')];
+}
diff --git a/challenge-245/peter-campbell-smith/perl/ch-2.pl b/challenge-245/peter-campbell-smith/perl/ch-2.pl
new file mode 100755
index 0000000000..a9f90640ff
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+++ b/challenge-245/peter-campbell-smith/perl/ch-2.pl
@@ -0,0 +1,69 @@
+#!/usr/bin/perl
+
+use v5.26;    # The Weekly Challenge - 2023-11-27
+use utf8;     # Week 245 task 2 - Largest of three
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+use Algorithm::Combinatorics 'combinations';
+
+my ($j, @digits);
+
+largest_of_three(8, 6, 7, 1, 0);
+largest_of_three(0);
+largest_of_three(18446744073709551614, 3);
+largest_of_three(333, 666, 1, 4, 7);
+
+# for $j (0..9) {
+	# push @digits, int(rand(10000));
+# }
+# largest_of_three(@digits);
+largest_of_three(13, 14, 1, 102);
+
+sub largest_of_three {
+	
+	my (@digits, $c, $iter, $comb, @set, $value, $result, $length);
+	
+	# loop over sizes of combination to consider
+	@digits = @_;
+	$result = -1;
+	$length = 0;
+	
+	for ($c = @digits; $c > 0; $c --) {
+		
+		# iterate over combinations of length $c numbers
+		$iter = combinations(\@digits, $c);
+		while ($comb = $iter->next) {
+			
+			# reverse sort them alphabetically to get best bet first
+			@set = reverse sort @$comb;
+			
+			# concatenate them and see if that's the best so far
+			$value = join('', @set);
+			
+			# this if is just: if (mult_of_3($value) and $value > $result) accommodating BigInts
+			if (is_mult_of_3($value) and (length($value) > $length
+					or (length($value) eq $length and $value gt $result))) {
+				$result = $value;
+				$length = length($result);
+			}
+		}
+		
+		# if we have an answer, no smaller subset will produce a larger number
+		last if $result >= 0;
+	}
+	
+	say qq[\nInput:  \@digits = (] . join(q[, ], @_) . q[)];
+	say qq[Output: $result];
+}
+
+sub is_mult_of_3 {
+	
+	my ($input, $sum);
+	
+	$input = shift;
+	$sum = 0;
+	$sum += $1 while $input =~ m|(\d)|g;
+	return $sum % 3 == 0;
+	
+}