3 files changed, 100 insertions, 0 deletions
diff --git a/challenge-219/peter-campbell-smith/blog.txt b/challenge-219/peter-campbell-smith/blog.txt
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index 0000000000..63ff558f03
--- /dev/null
+++ b/challenge-219/peter-campbell-smith/blog.txt
@@ -0,0 +1 @@
+http://ccgi.campbellsmiths.force9.co.uk/challenge/219
diff --git a/challenge-219/peter-campbell-smith/perl/ch-1.pl b/challenge-219/peter-campbell-smith/perl/ch-1.pl
new file mode 100644
index 0000000000..e2cce04ff1
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+++ b/challenge-219/peter-campbell-smith/perl/ch-1.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl
+
+use v5.16;    # The Weekly Challenge - 2023-05-29
+use utf8;     # Week 219 task 1 - Sorted squares
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+sorted_squares(-2, -1, 0, 3, 4);
+sorted_squares(5, -4, -1, 3, 6);
+sorted_squares(5.3, -77.62, 11, 0, 3.14159, 2.1728);
+
+sub sorted_squares {
+
+	# square the list items and then sort them
+	say qq[\nInput:  \@list = (] . join(', ', @_) . ')';
+	say qq[Output: (] . join (', ', sort { $a <=> $b } map { $_ ** 2 } @_) . ')';
+}
+
diff --git a/challenge-219/peter-campbell-smith/perl/ch-2.pl b/challenge-219/peter-campbell-smith/perl/ch-2.pl
new file mode 100644
index 0000000000..4319314099
--- /dev/null
+++ b/challenge-219/peter-campbell-smith/perl/ch-2.pl
@@ -0,0 +1,81 @@
+#!/usr/bin/perl
+
+use v5.16;    # The Weekly Challenge - 2023-05-29
+use utf8;     # Week 219 task 2 - Travel expenditure
+use strict;   # Peter Campbell Smith
+use warnings; # Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge
+
+my (@costs, @periods, @days, $best_cost, $best_explain);
+
+travel_exps([2, 7, 25], [1, 7, 30], [1, 5, 6, 7, 9, 15]);
+travel_exps([2, 7, 25], [1, 7, 30], [1, 2, 3, 5, 7, 10, 11, 12, 14, 20, 30, 31]);
+travel_exps([2, 7, 13], [1, 7, 14], [1, 2, 3, 5, 7, 10, 11, 12, 14, 20, 30, 31]);
+
+# generate longer example
+my ($j, @daysx);
+for $j (1 .. 100) {
+	push @daysx, $j if rand(1) < 0.4;
+}
+travel_exps([2, 7, 13], [1, 7, 14], \@daysx);
+
+
+sub travel_exps {
+	
+	# initialise
+	@costs = @{$_[0]};
+	@periods = @{$_[1]};
+	@days = @{$_[2]};
+	$best_explain = '';
+	$best_cost = 99999;
+	
+	# start recurive solution
+	buy_tickets(\@days, 0, '');
+	
+	# show results
+	say qq[\nInput:  \@costs   = (] . join(', ', @costs) . ')';
+	say qq[        \@periods = (] . join (', ', @periods) . ')';
+	say qq[        \@days    = (] . join (', ', @days) . ')';
+	say qq[Output: $best_cost = ] . substr($best_explain, 0, -2);
+}
+
+sub buy_tickets {
+	
+	my (@days_left, $cost, $purchase_day, $j, $valid_until, $explain, $explain2, $cost2, @days_left2);
+	
+	# initialise
+	@days_left = @{$_[0]};
+	$cost = $_[1];
+	$explain = $_[2];
+				
+	# try buying each type of ticket and see which days it covers
+	for ($j = 2; $j >= 0; $j --) {
+		$cost2 = $cost + $costs[$j];
+		@days_left2 = @days_left;
+		$purchase_day = $days_left2[0];
+		$explain2 = qq[$explain$periods[$j] day ticket on day $purchase_day, ];
+		$valid_until = $purchase_day + $periods[$j] - 1;
+		
+		# remove days now paid for
+		while (@days_left2 and $days_left2[0] <= $valid_until) {
+			shift @days_left2;
+		}
+		
+		# have we finished?
+		if (scalar @days_left2 == 0) {
+			
+			# is this the best deal
+			if ($cost2 < $best_cost) {
+				$best_cost = $cost2;
+				$best_explain = $explain2;
+			}
+
+		# buy more tickets to cover remaining days
+		} elsif ($cost2 < $best_cost) {
+			buy_tickets(\@days_left2, $cost2, $explain2);
+		}
+	}
+}
+
+			
+			
+	
+\ No newline at end of file