Task 2 done

1 files changed, 86 insertions, 0 deletions

diff --git a/challenge-129/luca-ferrari/raku/ch-2.p6 b/challenge-129/luca-ferrari/raku/ch-2.p6
new file mode 100644
index 0000000000..2863546afb
--- /dev/null
+++ b/challenge-129/luca-ferrari/raku/ch-2.p6
@@ -0,0 +1,86 @@
+#!raku
+
+class LL {
+    has Int $.value = -1;
+    has Bool $.available is rw = True;
+    has LL $.next is rw = LL;
+
+
+    method length() {
+        my $counter = 1;
+        my $current = self;
+        $counter++ && $current = $current.next while ( $current.next );
+        return $counter;
+    }
+
+
+    method pop-last() {
+        my $current  = self;
+        return Nil if ! $current.available;
+
+        while ( $current.available && $current.next && $current.next.available ) {
+            $current  = $current.next;
+        }
+
+        $current.available = False;
+        return $current;
+    }
+
+    method print() {
+        print $!value;
+        if ( $!next  ) {
+            print " -> ";
+            $!next.print;
+        }
+    }
+}
+
+
+sub MAIN() {
+    my $L1 = LL.new( value => 1 );
+    $L1.next = LL.new( value => 2 );
+    $L1.next.next = LL.new( value => 3 );
+    $L1.next.next.next = LL.new( value => 4 );
+    $L1.next.next.next.next = LL.new( value => 5 );
+
+    my $L2 = LL.new( value => 6 );
+    $L2.next = LL.new( value => 5 );
+    $L2.next.next = LL.new( value => 5 );
+
+    say "L1 = " ~ $L1.length;
+    say "L2 = " ~ $L2.length;
+
+    my ( $sum, $carry ) = 0, 0;
+    my @sums;
+    for 0 ..^ max( $L1.length, $L2.length ) {
+        my ( $a, $b ) = ( $L1.pop-last, $L2.pop-last );
+        my $sum = $carry
+                   + ( $a ?? $a.value !! 0 )
+                   + ( $b ?? $b.value !! 0 );
+
+        if ( $sum >= 10 ) {
+            $carry = ( $sum / 10 ).Int;
+            $sum %= 10;
+        }
+        else {
+            $carry = 0;
+        }
+
+        @sums.push: $sum;
+    }
+
+
+    my $R;
+    my $current;
+    my $previous;
+    for @sums {
+        $current = LL.new( value => $_, next => ( $previous ?? $previous !! Nil ) );
+        $previous = $current;
+    }
+
+    say $current.print;
+
+
+
+
+}