Challenge 49 Solutions

2 files changed, 91 insertions, 0 deletions

diff --git a/challenge-049/mark-anderson/raku/ch-1.p6 b/challenge-049/mark-anderson/raku/ch-1.p6
new file mode 100644
index 0000000000..37eef57c7e
--- /dev/null
+++ b/challenge-049/mark-anderson/raku/ch-1.p6
@@ -0,0 +1,8 @@
+#!/usr/bin/env perl6
+
+sub MAIN(Int $arg where $arg > 0) {
+    1 .. Inf             ==> 
+    map   { .fmt("%b") } ==> 
+    first { $_ %% $arg } ==>
+    say();
+}
diff --git a/challenge-049/mark-anderson/raku/ch-2.p6 b/challenge-049/mark-anderson/raku/ch-2.p6
new file mode 100644
index 0000000000..abe7f8a143
--- /dev/null
+++ b/challenge-049/mark-anderson/raku/ch-2.p6
@@ -0,0 +1,83 @@
+#!/usr/bin/env perl6
+
+class LRU {
+    has $.capacity;
+    has @!cache;
+    has %!index;
+    has %!value;
+
+    method set(Int $k, Int $v) {
+        if defined %!index{$k} {
+            self!update($k);
+        }
+
+        else {
+            if (@!cache.elems == $.capacity) {
+                %!value{shift @!cache}:delete;
+            }
+            
+            @!cache.push($k);
+            %!value{$k} = $v;
+            %!index = @!cache.kv.reverse; #this can be improved since all
+                                          #indexes don't need to be updated. 
+        }
+    } 
+
+    method get(Int $k) {
+        if defined %!index{$k} {
+            self!update($k);
+        }
+
+        return %!value{$k} // -1;
+    }
+
+    method !update(Int $k) {
+        my $i = %!index{$k};
+
+        unless ($i == $.capacity - 1) {
+            @!cache = (@!cache[0..$i-1], @!cache[$i+1..*-1], $k).flat;
+            %!index = @!cache.kv.reverse; # ditto
+        }
+    }
+
+    method printIt {
+        say "[least recently used] {@!cache.join(", ")} [most recently used]";
+        #say "Value = ", %!value;
+        #say "Index = ", %!index;
+        print "\n";
+    }
+}
+
+sub MAIN(Int $capacity where $capacity > 0) {
+    my $lru = LRU.new(capacity => $capacity);
+
+    say "capacity = {$lru.capacity}\n";
+ 
+    $lru.set(1, 3);
+
+    $lru.set(2, 5);
+
+    $lru.set(3, 7);
+
+    $lru.printIt;
+
+    $lru.get(2).say;
+
+    $lru.printIt;
+    
+    $lru.get(1).say;
+
+    $lru.printIt;
+
+    $lru.get(4).say;
+
+    $lru.printIt;
+
+    $lru.set(4, 9);
+
+    $lru.printIt;
+
+    $lru.get(3).say;
+
+    $lru.printIt;
+}