- Added Raku solutions to the "Reorder List" task.

2 files changed, 138 insertions, 0 deletions

diff --git a/challenge-068/mohammad-anwar/raku/ch-2.raku b/challenge-068/mohammad-anwar/raku/ch-2.raku
new file mode 100644
index 0000000000..25b737ca8a
--- /dev/null
+++ b/challenge-068/mohammad-anwar/raku/ch-2.raku
@@ -0,0 +1,64 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 068
+#
+# Task #2: Reorder List
+#
+# https://perlweeklychallenge.org/blog/perl-wee
+#
+
+class Node {
+    has Int  $.v;
+    has Node $.c;
+
+          method v()        { return $!v }
+    multi method c()        { return $!c }
+    multi method c(Node $c) { $!c = $c   }
+
+    method show-link() {
+        my $c = $!c;
+        my @v = ($!v);
+
+        while defined $c {
+            @v.push: $c.v;
+            $c = $c.c;
+        }
+
+        return @v.join(' -> ');
+    }
+}
+
+sub MAIN(Str :$linked-list? = '1 -> 2 -> 3 -> 4 -> 5') {
+    reorder-list($linked-list).show-link.say;
+}
+
+sub reorder-list(Str $linked-list is copy) {
+
+    $linked-list ~~ s:g/\s//;
+    my @list = $linked-list.split('->');
+    my $head = Node.new(v => @list.shift.Int);
+    my @link = ($head);
+
+    # prepare singly linked list
+    for @list -> $v {
+        my $node = Node.new(v => $v.Int);
+        @link.tail.c($node);
+        @link.push: $node;
+    }
+
+    # reorder linked list
+    my Int $min = 0;
+    my Int $max = (@list.elems/ 2).Int;
+    my Int $i   = 1;
+    for $min .. $max-1 {
+        my $last = @link.pop;
+        @link.splice($i, 0, $last);
+        @link.tail.c(Node);
+        @link[$i - 1].c($last);
+        @link[$i].c(@link[$i + 1]);
+        $i += 2;
+    }
+
+    return $head;
+}
diff --git a/challenge-068/mohammad-anwar/raku/ch-2a.raku b/challenge-068/mohammad-anwar/raku/ch-2a.raku
new file mode 100644
index 0000000000..06c86ac3ea
--- /dev/null
+++ b/challenge-068/mohammad-anwar/raku/ch-2a.raku
@@ -0,0 +1,74 @@
+#!/usr/bin/env raku
+
+#
+# Perl Weekly Challenge - 068
+#
+# Task #2: Reorder List
+#
+# https://perlweeklychallenge.org/blog/perl-wee
+#
+
+class Node {
+    has Int  $.v;
+    has Node $.c;
+
+          method v()        { return $!v }
+    multi method c()        { return $!c }
+    multi method c(Node $c) { $!c = $c   }
+
+    method show-link() {
+        my $c = $!c;
+        my @v = ($!v);
+
+        while defined $c {
+            @v.push: $c.v;
+            $c = $c.c;
+        }
+
+        return @v.join(' -> ');
+    }
+}
+
+use Test;
+
+is reorder-list('1 -> 2 -> 3 -> 4').show-link,
+   '1 -> 4 -> 2 -> 3',
+   'testing 1 -> 2 -> 3 -> 4';
+is reorder-list('1 -> 2 -> 3 -> 4 -> 5').show-link,
+   '1 -> 5 -> 2 -> 4 -> 3',
+   'testing 1 -> 2 -> 3 -> 4 -> 5';
+is reorder-list('1 -> 2 -> 3 -> 4 -> 5 -> 6').show-link,
+   '1 -> 6 -> 2 -> 5 -> 3 -> 4',
+   'testing 1 -> 2 -> 3 -> 4 -> 5 -> 6';
+
+done-testing;
+
+sub reorder-list(Str $linked-list is copy) {
+
+    $linked-list ~~ s:g/\s//;
+    my @list = $linked-list.split('->');
+    my $head = Node.new(v => @list.shift.Int);
+    my @link = ($head);
+
+    # prepare singly linked list
+    for @list -> $v {
+        my $node = Node.new(v => $v.Int);
+        @link.tail.c($node);
+        @link.push: $node;
+    }
+
+    # reorder linked list
+    my Int $min = 0;
+    my Int $max = (@list.elems/ 2).Int;
+    my Int $i   = 1;
+    for $min .. $max-1 {
+        my $last = @link.pop;
+        @link.splice($i, 0, $last);
+        @link.tail.c(Node);
+        @link[$i - 1].c($last);
+        @link[$i].c(@link[$i + 1]);
+        $i += 2;
+    }
+
+    return $head;
+}