- Added solutions by Arne Sommer.

- Added solutions by Athanasius.
- Added solutions by PokGoPun.
- Added solutions by Laurent Rosenfeld.

3 files changed, 29 insertions, 0 deletions

diff --git a/challenge-261/laurent-rosenfeld/blog1.txt b/challenge-261/laurent-rosenfeld/blog1.txt
new file mode 100644
index 0000000000..83ce046aae
--- /dev/null
+++ b/challenge-261/laurent-rosenfeld/blog1.txt
@@ -0,0 +1 @@
+https://blogs.perl.org/users/laurent_r/2024/03/perl-weekly-challenge-261-multiply-by-two.html
diff --git a/challenge-261/laurent-rosenfeld/perl/ch-2.pl b/challenge-261/laurent-rosenfeld/perl/ch-2.pl
new file mode 100644
index 0000000000..b77de6c889
--- /dev/null
+++ b/challenge-261/laurent-rosenfeld/perl/ch-2.pl
@@ -0,0 +1,17 @@
+use strict;
+use warnings;
+use feature 'say';
+
+sub multiply_by_two {
+    my $start = shift;
+    die "$start cannot be 0" if $start == 0;
+    my %present = map { $_ => 1 } @_;
+    $start *= 2 while $present{$start};
+    return $start;
+}
+
+my @tests = ( [3, [5,3,6,1,12]], [1, [1,2,4,3]], [2, [5,6,7]] );
+for my $test (@tests) {
+    printf "%d - %-15s => ", $test->[0], "@{$test->[1]}";
+    say multiply_by_two @$test[0], @{$test->[1]};
+}
diff --git a/challenge-261/laurent-rosenfeld/raku/ch-2.raku b/challenge-261/laurent-rosenfeld/raku/ch-2.raku
new file mode 100644
index 0000000000..67860cd2f3
--- /dev/null
+++ b/challenge-261/laurent-rosenfeld/raku/ch-2.raku
@@ -0,0 +1,11 @@
+sub multiply-by-two ($start is copy where * != 0, @in) {
+    my $bag = @in.Bag;
+    $start *= 2 while $bag{$start};
+    return $start;
+}
+
+my @tests = (3, (5,3,6,1,12)), (1, (1,2,4,3)), (2, (5,6,7));
+for @tests -> @test {
+    printf "%d - %-15s => ", @test[0], "@test[1]";
+    say multiply-by-two @test[0], @test[1];
+}