6 files changed, 191 insertions, 1 deletions
diff --git a/challenge-055/mohammad-anwar/blog.txt b/challenge-055/mohammad-anwar/blog.txt
new file mode 100644
index 0000000000..cec66e9fda
--- /dev/null
+++ b/challenge-055/mohammad-anwar/blog.txt
@@ -0,0 +1 @@
+https://perlweeklychallenge.org/blog/weekly-challenge-055
diff --git a/challenge-055/mohammad-anwar/perl/ch-1.pl b/challenge-055/mohammad-anwar/perl/ch-1.pl
index 698f8ec222..62cd6d2986 100644
--- a/challenge-055/mohammad-anwar/perl/ch-1.pl
+++ b/challenge-055/mohammad-anwar/perl/ch-1.pl
@@ -3,7 +3,7 @@
 use strict;
 use warnings;
 
-my $binary_str = $ARGV[0];
+my $binary_str = $ARGV[0] // "101";
 
 print "$binary_str => ", flip_binary($binary_str), "\n";
 
diff --git a/challenge-055/mohammad-anwar/perl/ch-2.pl b/challenge-055/mohammad-anwar/perl/ch-2.pl
new file mode 100644
index 0000000000..698d68671d
--- /dev/null
+++ b/challenge-055/mohammad-anwar/perl/ch-2.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Algorithm::Combinatorics qw(permutations);
+
+my $N = $ARGV[0] // 4;
+
+my $wave = fetch_wave_array($N);
+map { print sprintf("[%s]\n", join(",", @$_)) } @$wave;
+
+sub fetch_wave_array {
+    my ($N) = @_;
+
+    die "ERROR: Invalid array size [$N]\n" unless ($N =~ /^\d+$/ && $N > 0);
+
+    my $iter = permutations([ 1..$N ]);
+    my $wave = [];
+    while (my $array = $iter->next) {
+        push @$wave, $array if is_wave($array);
+    }
+
+    return $wave;
+}
+
+sub is_wave {
+    my ($array) = @_;
+
+    my $is_wave = 1;
+    foreach my $i (1..$#$array) {
+        ($i % 2)
+        ?
+        ($array->[$i] <= $array->[$i-1])
+        :
+        ($array->[$i] >= $array->[$i-1])
+        and next;
+
+        $is_wave = 0;
+        last;
+    }
+
+    return $is_wave;
+}
diff --git a/challenge-055/mohammad-anwar/perl/ch-2a.pl b/challenge-055/mohammad-anwar/perl/ch-2a.pl
new file mode 100644
index 0000000000..109bcc116a
--- /dev/null
+++ b/challenge-055/mohammad-anwar/perl/ch-2a.pl
@@ -0,0 +1,54 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More;
+use Test::Deep;
+use Algorithm::Combinatorics qw(permutations);
+
+my $unit_tests = {
+    1 => [ [1] ],
+    2 => [ [2,1] ],
+    3 => [ [2,1,3], [3,1,2] ],
+    4 => [ [2,1,4,3], [3,1,4,2], [3,2,4,1], [4,1,3,2], [4,2,3,1] ],
+};
+
+foreach my $size (sort { $a <=> $b } keys %$unit_tests) {
+    cmp_deeply(fetch_wave_array($size), $unit_tests->{$size}, "array size $size.");
+}
+
+done_testing;
+
+sub fetch_wave_array {
+    my ($N) = @_;
+
+    die "ERROR: Invalid array size [$N]\n" unless ($N =~ /^\d+$/ && $N > 0);
+
+    my $iter = permutations([ 1..$N ]);
+    my $wave = [];
+    while (my $array = $iter->next) {
+        push @$wave, $array if is_wave($array);
+    }
+
+    return $wave;
+}
+
+sub is_wave {
+    my ($array) = @_;
+
+    my $is_wave = 1;
+    foreach my $i (1..$#$array) {
+        ($i % 2)
+        ?
+        ($array->[$i] <= $array->[$i-1])
+        :
+        ($array->[$i] >= $array->[$i-1])
+        and next;
+
+        $is_wave = 0;
+        last;
+    }
+
+    return $is_wave;
+}
diff --git a/challenge-055/mohammad-anwar/raku/ch-2.p6 b/challenge-055/mohammad-anwar/raku/ch-2.p6
new file mode 100644
index 0000000000..d15c8cbf96
--- /dev/null
+++ b/challenge-055/mohammad-anwar/raku/ch-2.p6
@@ -0,0 +1,44 @@
+#!/usr/bin/env perl6
+
+use v6.c;
+
+multi sub MAIN(*@) is hidden-from-USAGE {
+    say $*USAGE;
+    say "\nERROR: Invalid array size !!!";
+}
+
+multi sub MAIN(Int :$N = 4) {
+    my @wave = fetch-wave-array($N);
+    @wave.map({ print sprintf("[%s]\n", join(",", @$_)) });
+}
+
+sub fetch-wave-array($size) {
+    die "ERROR: Invalid array size [$size]\n"
+        unless ($size ~~ /^\d+$/ && $size > 0);
+
+    my @N = (1 .. $size).permutations();
+    my @wave = ();
+    for @N -> @array {
+        push @wave, @array if is-wave(@array);
+    }
+
+    return @wave;
+}
+
+sub is-wave(@array) {
+
+    my $is-wave = 1;
+    for 1 .. @array.elems-1 -> $i {
+        ($i mod 2 == 1)
+        ??
+        (@array[$i] <= @array[$i-1])
+        !!
+        (@array[$i] >= @array[$i-1])
+        and next;
+
+        $is-wave = 0;
+        last;
+    }
+
+    return $is-wave;
+}
diff --git a/challenge-055/mohammad-anwar/raku/ch-2a.p6 b/challenge-055/mohammad-anwar/raku/ch-2a.p6
new file mode 100644
index 0000000000..d49567bc31
--- /dev/null
+++ b/challenge-055/mohammad-anwar/raku/ch-2a.p6
@@ -0,0 +1,47 @@
+#!/usr/bin/env perl6
+
+use Test;
+
+my $unit-tests = :{
+    1 => [ (1,), ],
+    2 => [ (2,1), ],
+    3 => [ (2,1,3), (3,1,2) ],
+    4 => [ (2,1,4,3), (3,1,4,2), (3,2,4,1), (4,1,3,2), (4,2,3,1) ]
+};
+
+for $unit-tests.keys.sort -> $size {
+    is-deeply(fetch-wave-array($size), $unit-tests{$size}, "array size $size");
+}
+
+done-testing;
+
+sub fetch-wave-array($size) {
+    die "ERROR: Invalid array size [$size]\n"
+        unless ($size ~~ /^\d+$/ && $size > 0);
+
+    my @N = (1 .. $size).permutations();
+    my $wave = [];
+    for @N -> @array {
+        push @$wave, @array if is-wave(@array);
+    }
+
+    return $wave;
+}
+
+sub is-wave(@array) {
+
+    my $is-wave = 1;
+    for 1 .. @array.elems-1 -> $i {
+        ($i mod 2 == 1)
+        ??
+        (@array[$i] <= @array[$i-1])
+        !!
+        (@array[$i] >= @array[$i-1])
+        and next;
+
+        $is-wave = 0;
+        last;
+    }
+
+    return $is-wave;
+}