Challenge 101 Solutions (Raku)

2 files changed, 38 insertions, 3 deletions

diff --git a/challenge-101/mark-anderson/raku/ch-1.raku b/challenge-101/mark-anderson/raku/ch-1.raku
index 030a85523d..00dbaa4d0c 100644
--- a/challenge-101/mark-anderson/raku/ch-1.raku
+++ b/challenge-101/mark-anderson/raku/ch-1.raku
@@ -40,7 +40,7 @@ is-deeply pack-a-spiral(1..144),
 
 sub pack-a-spiral(@A is copy)
 {
-    my $f = tightest-factor(@A.elems);
+    my $f = tightest-factor(+@A);
     my @k = @A.keys.rotor($f);
     @k = spiral(@k.map(*.Array).Array);
     @A[@k] = @A;
@@ -52,8 +52,8 @@ sub tightest-factor($n)
     return $n if $n.is-prime;
     my $s = sqrt($n);
     return $s if $s.narrow ~~ UInt;
-    my @f = grep { $n %% $_ }, 2..$n/2;
-    return @f[@f/2];
+    my @f = grep { $n %% $_ }, 2..$n div 2;
+    return @f[+@f div 2];
 }
 
 #
diff --git a/challenge-101/mark-anderson/raku/ch-2.raku b/challenge-101/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..d06aaa6861
--- /dev/null
+++ b/challenge-101/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,35 @@
+#!/usr/bin/env raku
+
+# With help from https://www.geeksforgeeks.org/check-whether-a-given-point-lies-inside-a-triangle-or-not/
+
+use Test;
+plan 3;
+
+nok contains-origin((1,1), (0,2),  (0,3));
+ok  contains-origin((1,1), (-1,1), (0,-3));
+ok  contains-origin((0,1), (2,0),  (-6,0));
+
+class point 
+{
+    has Int $.x;
+    has Int $.y;
+}
+
+sub area($a, $b, $c)
+{
+    abs(($a.x * ($b.y - $c.y)) + 
+        ($b.x * ($c.y - $a.y)) + 
+        ($c.x * ($a.y - $b.y))) / 2; 
+}
+
+sub contains-origin($A, $B, $C) 
+{
+    my $a = point.new(x => $A[0], y => $A[1]);
+    my $b = point.new(x => $B[0], y => $B[1]);
+    my $c = point.new(x => $C[0], y => $C[1]);
+    my $p = point.new(:0x, :0y);
+
+   .UInt given area($a, $b, $c) == area($a, $b, $p) + 
+                                   area($b, $c, $p) + 
+                                   area($a, $c, $p); 
+}