- Added Raku solution to "Left Rotation" task.

2 files changed, 100 insertions, 0 deletions

diff --git a/challenge-078/mohammad-anwar/raku/ch-2.raku b/challenge-078/mohammad-anwar/raku/ch-2.raku
new file mode 100644
index 0000000000..85c0cbc761
--- /dev/null
+++ b/challenge-078/mohammad-anwar/raku/ch-2.raku
@@ -0,0 +1,47 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 078
+#
+# Task #2: Left Rotation
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-078
+#
+
+use v6.d;
+
+sub MAIN(Str :$A = "10, 20, 30, 40, 50", Str :$B = "3, 4") {
+    left-rotation($A, $B).join("\n").say;
+}
+
+#
+#
+# METHOD
+
+sub left-rotation(Str $source, Str $index) {
+
+    die "ERROR: Invalid source [$source].\n"
+        unless $source ~~ /^[\-?\d\,?\s?]+$/;
+    die "ERROR: Invalid index  [$index].\n"
+        unless $index  ~~ /^[\-?\d\,?\s?]+$/;
+
+    my @source = $source.split(',').map: { .Int };
+    my @index  = $index.split(',').map:  { .Int };
+
+    my @left-rotation = Empty;
+    for @index -> $i {
+        my @array = Empty;
+        for $i..@source.elems-1 -> $j {
+            @array.push: @source.[$j];
+        }
+        if $i > 0 {
+            for 0..$i-1 -> $k {
+                @array.push: @source.[$k];
+            }
+        }
+
+        @left-rotation.push: @array;
+    }
+
+    return |@left-rotation;
+}
diff --git a/challenge-078/mohammad-anwar/raku/ch-2.t b/challenge-078/mohammad-anwar/raku/ch-2.t
new file mode 100644
index 0000000000..6fc555f1a0
--- /dev/null
+++ b/challenge-078/mohammad-anwar/raku/ch-2.t
@@ -0,0 +1,53 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 078
+#
+# Task #2: Left Rotation
+#
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-078
+#
+
+use Test;
+
+is-deeply [left-rotation("10, 20, 30, 40, 50", "3, 4")],
+          [[40, 50, 10, 20, 30], [50, 10, 20, 30, 40]],
+          "testing example 1";
+
+is-deeply [left-rotation("7, 4, 2, 6, 3", "1, 3, 4")],
+          [[4, 2, 6, 3, 7], [6, 3, 7, 4, 2], [3, 7, 4, 2, 6]],
+          "testing example 2";
+
+done-testing;
+
+#
+#
+# METHOD
+
+sub left-rotation(Str $source, Str $index) {
+
+    die "ERROR: Invalid source [$source].\n"
+        unless $source ~~ /^[\-?\d\,?\s?]+$/;
+    die "ERROR: Invalid index  [$index].\n"
+        unless $index  ~~ /^[\-?\d\,?\s?]+$/;
+
+    my @source = $source.split(',').map: { .Int };
+    my @index  = $index.split(',').map:  { .Int };
+
+    my @left-rotation = Empty;
+    for @index -> $i {
+        my @array = Empty;
+        for $i..@source.elems-1 -> $j {
+            @array.push: @source.[$j];
+        }
+        if $i > 0 {
+            for 0..$i-1 -> $k {
+                @array.push: @source.[$k];
+            }
+        }
+
+        @left-rotation.push: @array;
+    }
+
+    return |@left-rotation;
+}