- Added solutions by Colin Crain.

2 files changed, 76 insertions, 0 deletions

diff --git a/challenge-059/colin-crain/raku/ch-1.p6 b/challenge-059/colin-crain/raku/ch-1.p6
new file mode 100644
index 0000000000..b6c5975aee
--- /dev/null
+++ b/challenge-059/colin-crain/raku/ch-1.p6
@@ -0,0 +1,65 @@
+class Node {
+    has Int  $.value is rw;
+    has Node $.next  is rw;
+}
+
+class LinkedList {
+    has Node $.first is rw;
+    has Node $.last  is rw;
+
+    method populate_from_array ( @array ) {
+        my $node;
+        my $next;
+        while @array.elems > 0 {
+            $node = Node.new(value => @array.pop.Int);
+            $node.next = $next if $next.defined;
+            $next = $node;
+        }
+        $.first = $node;
+    }
+
+    method arrow_print () {
+        my @output;
+        my $node = $.first;
+        while (defined $node) {
+            push @output, $node.value;
+            $node = $node.next;
+        }
+        @output.join(' → ').say;
+    }
+}
+
+
+sub MAIN (Int:D $locus, *@input) {
+
+    ## 1. convert the input commandline array into a linked list
+    my $list = LinkedList.new();
+    $list.populate_from_array( @input );
+
+    my $before = LinkedList.new();
+    my $after  = LinkedList.new();
+    my $node   = $list.first;
+
+    ## 2a. if it is less than the given value, add it to
+    ##     the end of the before list
+    ## 2b. if it is more than or equal to the given value
+    ##     add it to the end of the after list
+    ## if a sublist isn't started, start it with the node
+    while $node.defined {
+        my $sublist = $node.value < $locus ?? $before !! $after;
+        $sublist.last.defined ?? $sublist.last.next
+                              !! $sublist.first       = $node;
+        $sublist.last = $node;
+        $node = $node.next;
+    }
+
+    ## 3. link the pre list to the post list:
+    ## 3a. point the last element of the pre list to
+    ##     the first element of the post
+    ## 3b. point the last element of the post list to null
+    $before.last.next = $after.first if defined $before.last;
+    $after.last.next  = Nil if defined $after.last;
+
+    # output
+    $list.arrow_print();
+}
diff --git a/challenge-059/colin-crain/raku/ch-2.p6 b/challenge-059/colin-crain/raku/ch-2.p6
new file mode 100644
index 0000000000..6a9add0bfe
--- /dev/null
+++ b/challenge-059/colin-crain/raku/ch-2.p6
@@ -0,0 +1,11 @@
+sub MAIN ( *@input ) {
+
+    my @sets = @input.combinations: 2;
+    my $sum = [+] @sets.map({bit_difference($_)});
+
+    $sum.say;
+}
+
+sub bit_difference ($array) {
+    return ([+^] |$array).base(2).comb.sum;
+}