Solution to task 1

1 files changed, 23 insertions, 0 deletions

diff --git a/challenge-080/jo-37/perl/ch-1.pl b/challenge-080/jo-37/perl/ch-1.pl
new file mode 100755
index 0000000000..90c9bdce69
--- /dev/null
+++ b/challenge-080/jo-37/perl/ch-1.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/perl
+
+use Test2::V0;
+
+# Find the smallest positive number not in given set.
+sub missing_number {
+
+	# Find the first gap within the sorted positive numbers and zero.
+	my $prev = 0;
+	foreach (sort {$a <=> $b} grep $_ > 0, @_) {
+		last if $_ - $prev > 1;
+		$prev = $_;
+	}
+
+	# Successor is the smallest number missing in set.
+	$prev + 1;
+}
+is missing_number(5, 2, -2, 0), 1, 'first example';
+is missing_number(1, 8, -1), 2, 'second example';
+is missing_number(2, 0, -1), 1, 'third example';
+is missing_number(-1, 1, 2, 3), 4, 'no gap in set';
+
+done_testing;