Challenge 048 task 1

1 files changed, 36 insertions, 0 deletions

diff --git a/challenge-048/jo-37/perl/ch-1.pl b/challenge-048/jo-37/perl/ch-1.pl
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+++ b/challenge-048/jo-37/perl/ch-1.pl
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+#!/usr/bin/perl -s
+
+use v5.16;
+use warnings;
+use experimental 'signatures';
+
+our $help;
+
+die <<EOS if $help;
+usage: $0 [-help] [N]
+
+-help
+    print this help text
+
+N
+    find the survivor out of N
+
+EOS
+
+
+### Input and Output
+
+say survivor(shift // 50);
+
+
+### Implementation
+#
+# Instead of a circle, we consider a row where the first is moved to the
+# end in each step.
+
+sub survivor ($n) {
+	my @row = (1 .. $n);
+    push @row, (splice @row, 0, 2)[0] while @row > 1;
+
+    $row[0];
+}