Try some bitwise operations

1 files changed, 60 insertions, 3 deletions

diff --git a/misc/cards/main.rb b/misc/cards/main.rb
index c2163ec..a8f2c1d 100644
--- a/misc/cards/main.rb
+++ b/misc/cards/main.rb
@@ -4,6 +4,17 @@ end
 
 class Card
   attr_reader :raw, :prefix, :letter, :number
+  BITS = {
+    "+" => 256,
+    "-" => 128,
+    "=" => 64,
+    "A" => 32,
+    "B" => 16,
+    "C" => 8,
+    "1" => 4,
+    "2" => 2,
+    "3" => 1,
+  }
 
   def initialize(raw)
     @raw = raw
@@ -12,12 +23,25 @@ class Card
     @number = raw[1..-1].size
   end
 
+  def <=>(other)
+    self.score <=> other.score
+  end
+
+  def score
+    @score ||= begin
+      score = 0
+      score += BITS[prefix]
+      score += BITS[letter]
+      score += BITS[number.to_s]
+      score
+    end
+  end
+
   def match?(*others)
     others << self
-
     [:prefix, :letter, :number].each do |property|
-      count = others.map(&property).uniq.count
-      return false if count != 1 && count != others.size
+      x = others.map(&property).uniq.count
+      return false if x != 1 && x != others.size
     end
 
     true
@@ -43,6 +67,7 @@ class Solution
         y = cache[cards[p]]
         for q in (p+1...cards.size)
           z = cache[cards[q]]
+
           if x.match?(y, z)
             return [x, y, z].join(' ')
           end
@@ -52,6 +77,38 @@ class Solution
 
     ""
   end
+
+=begin
+|4|2|1|
+|+|-|=|
+
+|4|2|1|
+|A|B|C|
+
+123
+
+|256|128| 64| 32| 16|  8|  4|  2|  1|
+|  +|  -|  =|  A|  B|  C|  1|  2|  3|
+
+-A: 128 + 32 + 3
+-B: 128 + 16 + 3
+
+=end
+  def run(row)
+    cards = row.split.map { |x| Card.new(x) }
+    for i in (0...cards.size)
+      x = cards[i]
+      for p in (i+1...cards.size)
+        y = cards[p]
+        for q in (p+1...cards.size)
+          z = cards[q]
+          return [x, y, z].join(' ') if x.match?(y, z)
+        end
+      end
+    end
+
+    ""
+  end
 end
 
 assert_equal(true, Card.new("+C").match?(Card.new("-CC"), Card.new("=CCC")))