Initial 257 (Raku)

2 files changed, 67 insertions, 0 deletions

diff --git a/challenge-257/mark-anderson/raku/ch-1.raku b/challenge-257/mark-anderson/raku/ch-1.raku
new file mode 100644
index 0000000000..3bd8f8f5c4
--- /dev/null
+++ b/challenge-257/mark-anderson/raku/ch-1.raku
@@ -0,0 +1,12 @@
+#!/usr/bin/env raku
+use Test;
+
+is-deeply smaller-than-current(5,2,1,6), (2,1,0,3);
+is-deeply smaller-than-current(1,2,0,3), (1,2,0,3);
+is-deeply smaller-than-current(0,1),     (0,1);
+is-deeply smaller-than-current(9,4,9,2), (2,1,2,0);
+
+sub smaller-than-current(*@a)
+{
+    @a.sort.unique.antipairs.Hash{@a}
+}
diff --git a/challenge-257/mark-anderson/raku/ch-2.raku b/challenge-257/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..fdca8d6a20
--- /dev/null
+++ b/challenge-257/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,55 @@
+#!/usr/bin/env raku
+use Test;
+
+ok  echelon([1,0,0,1],
+            [0,1,0,2],
+            [0,0,1,3]);
+
+nok echelon([1, 1, 0],
+            [0, 1, 0],
+            [0, 0, 0]);
+
+ok  echelon([0, 1,-2, 0, 1],
+            [0, 0, 0, 1, 3],
+            [0, 0, 0, 0, 0],
+            [0, 0, 0, 0, 0]);
+
+ok  echelon([1, 0, 0, 4],
+            [0, 1, 0, 7],
+            [0, 0, 1,-1]);
+
+nok echelon([0, 1,-2, 0, 1],
+            [0, 0, 0, 0, 0],
+            [0, 0, 0, 1, 3],
+            [0, 0, 0, 0, 0]);
+
+nok echelon([0, 1, 0],
+            [1, 0, 0],
+            [0, 0, 0]);
+
+nok echelon([4, 0, 0, 0],
+            [0, 1, 0, 7],
+            [0, 0, 1,-1]);
+
+sub echelon(+@m)
+{
+    my @first = @m>>.first(*.so, :kv);
+    my $k = @first.first(*.so.not, :k);
+
+    # if rows are all 0 then they are grouped at the bottom
+    if $k { return False unless so @first[$k..*].all eqv (Any) }
+
+    my @non-zeroes = quietly @first[^$k] || @first;
+
+    # first non-zero number in rows (without all zeroes) is a 1
+    return False unless so @non-zeroes>>.[1].all == 1;
+
+    # 1 is to the right of the 1 in the row above
+    return False unless [<] @non-zeroes>>[0];
+
+    # leading zero cols are all 0 (except for the 1)
+    return all @non-zeroes>>[0].map({
+                                        all @m[*;$_].sum == 1,
+                                        all(@m[*;$_].Bag.keys) ~~ 0..1 
+                                    })
+}