1 files changed, 56 insertions, 0 deletions
diff --git a/challenge-085/shawn-wagner/perl/ch-1.pl b/challenge-085/shawn-wagner/perl/ch-1.pl
new file mode 100755
index 0000000000..01d46f4539
--- /dev/null
+++ b/challenge-085/shawn-wagner/perl/ch-1.pl
@@ -0,0 +1,56 @@
+#!/usr/bin/env perl
+use warnings;
+use strict;
+use feature qw/say state/;
+use experimental qw/postderef/;
+use List::Util qw/sum any/;
+
+# Could use Algorithm::Combinatorics or Math::Combinatorics here...
+
+
+
+BEGIN {
+  eval {
+    require Bit::Fast;
+    Bit::Fast->import(qw/popcount/);
+    1;
+  } or eval {
+    sub popcount {
+      my $binary = unpack "b*", pack("i", $_[0]);
+      return $binary =~ tr/1/1/;
+    }
+  };
+
+  # Optionally use Algorithm::Combinatorics
+  eval {
+    require Algorithm::Combinatorics;
+    Algorithm::Combinatorics->import(qw/combinations/);
+    1;
+  } or eval {
+    sub combinations {
+        state %cache;
+        my ($items, $r) = @_;
+        my $n = @$items;
+        if (!exists $cache{$n}->{$r}) {
+          my $max = (1 << $n) - 1;
+          for my $c (grep { popcount($_) == $r } 1 .. $max) {
+            push @{$cache{$n}->{$r}}, [ grep { $c & (1 << $_) } 0 .. $n - 1 ];
+          }
+        }
+        return map { [ $items->@[@$_] ] } $cache{$n}->{$r}->@*;
+      }
+  }
+}
+
+
+sub task1 {
+  if (any { my $total = sum @$_; 1 < $total && $total < 2 } combinations(\@_, 3)) {
+    say 1;
+  } else {
+    say 0;
+  }
+}
+
+task1(1.2, 0.4, 0.1, 2.5);
+task1(0.2, 1.5, 0.9, 1.1);
+task1(0.5, 1.1, 0.3, 0.7);