ch-2.p6

2 files changed, 79 insertions, 43 deletions

diff --git a/challenge-087/mark-anderson/raku/ch-1.p6 b/challenge-087/mark-anderson/raku/ch-1.p6
deleted file mode 100644
index e2e9753b02..0000000000
--- a/challenge-087/mark-anderson/raku/ch-1.p6
+++ /dev/null
@@ -1,43 +0,0 @@
-multi MAIN(*@n where .all ~~ Int) {
-    my @seqs = get-longest-seqs(@n);
-
-    @seqs = @seqs.map(*.join(", ").List);
-
-    .say for @seqs or 0;
-}
-
-multi MAIN {
-    use Test;
-    plan 3;
-
-    cmp-ok get-longest-seqs([100, 4, 50, 3, 2]), 
-           &[eqv], [(2, 3, 4),], "Example 1";
-
-    cmp-ok get-longest-seqs([20, 30, 10, 40, 50]),
-           &[eqv], [], "Example 2"; 
-    
-    cmp-ok get-longest-seqs([20, 19, 9, 11, 10]), 
-           &[eqv], [(9, 10, 11),], "Example 3";
-}
-
-sub get-longest-seqs(@n) {
-    my %h; 
-    @n = @n.sort.unique;
-
-    while @n {
-        my $seq = @n.splice(0, get-index(@n));
-        %h{$seq} = $seq.elems if $seq > 1;
-    }
-
-    sub get-index(@n) {
-        for ^@n -> $i {
-            unless @n[0..$i] == @n[0]..@n[$i] {
-                return $i;
-            }
-        }
-
-        return @n.elems;
-    }
-
-    [gather take .key.split(/\s/).map(+*).List for %h.maxpairs.sort];
-}
diff --git a/challenge-087/mark-anderson/raku/ch-2.p6 b/challenge-087/mark-anderson/raku/ch-2.p6
new file mode 100644
index 0000000000..795f1235ea
--- /dev/null
+++ b/challenge-087/mark-anderson/raku/ch-2.p6
@@ -0,0 +1,79 @@
+use Test;
+plan 4;
+
+my @example1 = < 0 0 0 1 0 1 >,
+               < 1 1 1 0 0 0 >,
+               < 0 0 1 0 0 1 >,
+               < 1 1 1 1 1 0 >,
+               < 1 1 1 1 1 0 >;
+
+my @example2 = < 1 0 1 0 1 0 >,
+               < 0 1 0 1 0 1 >,
+               < 1 0 1 0 1 0 >,
+               < 0 1 0 1 0 1 >;
+               
+my @example3 = < 0 0 0 1 1 1 >,
+               < 1 1 1 1 1 1 >,
+               < 0 0 1 0 0 1 >,
+               < 0 0 1 1 1 1 >,
+               < 0 0 1 1 1 1 >;
+
+my @example4 = < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >,
+               < 0 0 1 1 >;
+
+cmp-ok get-max-rectangle(@example1), &[eqv], [[1,1,1,1,1] xx 2], "Example 1";
+
+ok get-max-rectangle(@example2)        ==    0,                  "Example 2";
+
+cmp-ok get-max-rectangle(@example3), &[eqv], [[1,1,1,1] xx 2],   "Example 3";
+
+cmp-ok get-max-rectangle(@example4), &[eqv], [[1,1] xx 8],       "Example 4";
+
+sub get-max-rectangle(@matrix) {
+    my @drawing;
+    my @max-rectangle;
+    my $max-area = 0;
+    my $cols = @matrix[0].elems;
+    my @histogram = 0 xx $cols;
+
+    for @matrix -> @row {
+        for ^@row -> $i {
+            @histogram[$i] = @row[$i] ?? @histogram[$i]+1 !! 0;
+        }
+
+        get-drawing();
+        check-for-rectangles();
+    }
+
+    return @max-rectangle || 0;
+
+    sub get-drawing {
+        @drawing = Empty;
+        for @histogram.max-1...0 -> $r {
+            for ^$cols -> $c {
+                @drawing.push: @histogram[$c] > $r ?? 1 !! 0;
+            }
+        }
+        @drawing = @drawing.rotor($cols).map(*.join);
+    }
+
+    sub check-for-rectangles {
+        for ^@drawing.end -> $i {
+            for @drawing[$i] ~~ m:g/1+/ -> $m {
+                my $width  = $m.to - $m.from;
+                my $height = min @histogram[$m.from..$m.to-1];
+                my $area   = $width * $height;
+                if $area > $max-area {
+                    $max-area = $area;
+                    @max-rectangle = [1 xx $width] xx $height;
+                }
+            }
+        }
+    }
+}