minor optimization
[rubyvote] / lib / rubyvote / condorcet.rb
index 96a103b..4dd1745 100644 (file)
@@ -33,6 +33,8 @@
 
 class CondorcetVote < ElectionVote
 
+  attr_accessor :results
+
   def initialize(votes=nil)
     unless defined?(@candidates)
       @candidates = Array.new
@@ -44,6 +46,7 @@ class CondorcetVote < ElectionVote
       end
     end
     super(votes)
+    @results = Array.new
   end
 
   def tally_vote(vote=nil)
@@ -56,14 +59,13 @@ class CondorcetVote < ElectionVote
       if vote.length - 1 == index
         losers = []
       else
-        losers = vote.last( vote.flatten.length - index )
+        losers = vote.flatten.last( vote.flatten.length - index - 1)
       end
 
       losers.each do |place|
         place = [place] unless place.class == Array
         place.each do |loser|
           
-          next if winner == loser
 
           @votes[winner] = Hash.new unless @votes.has_key?(winner)
           @votes[loser] = Hash.new unless @votes.has_key?(loser)
@@ -81,27 +83,45 @@ class CondorcetVote < ElectionVote
     end
   end
 
-  def result
-    top_result = resultFactory( self )
-    until @candidates.empty?
-      aResult = resultFactory( self )
-      top_result.full_results << aResult
-      filter_out(aResult)
+  def results
+    if @results.size < 2 && (not @candidates.empty?)
+      tabulate
     end
-    top_result
+    @results
+  end
+
+  def result
+    find_only_winner unless @winner
+    @winner
   end
 
   protected
+
   def verify_vote(vote=nil)
     vote.instance_of?( Array ) and
       vote == vote.uniq
   end
 
+  def tabulate
+    find_only_winner unless @winner
+    until @candidates.empty? 
+      aResult = resultFactory( self )
+      @results << aResult.winners
+      filter_out(aResult)
+    end
+  end
+
+  def find_only_winner
+    @winner = resultFactory( self )
+    @results << @winner.winners
+    filter_out(@winner)
+  end
+
 end
 
 class PureCondorcetVote < CondorcetVote
-  def resultFactory(init)
-    PureCondorcetResult.new(init)
+  def result
+    PureCondorcetResult.new(self)
   end
 end
 
@@ -109,6 +129,7 @@ class CloneproofSSDVote < CondorcetVote
   def resultFactory(init)
     CloneproofSSDResult.new(init)
   end
+
 end
 
 
@@ -133,6 +154,7 @@ class CondorcetResult < ElectionResult
     votes = @election.votes unless votes
 
     defeats = Array.new
+    candidates = [candidates] unless candidates.class == Array
     candidates.each do |candidate|
       candidates.each do |challenger|
         next if candidate == challenger
@@ -204,14 +226,18 @@ class CloneproofSSDResult < CondorcetResult
       # see the array with the standard defeats
       transitive_defeats = self.defeats(candidates, votes)
 
+      candidates = [candidates] unless candidates.class == Array
       candidates.each do |cand1|
         candidates.each do |cand2|
-          candidates.each do |cand3|
-            if transitive_defeats.include?( [ cand2, cand1 ] ) and
-                transitive_defeats.include?( [ cand1, cand3 ] ) and
-                not transitive_defeats.include?( [ cand2, cand3 ] ) and
-                not cand2 == cand3
-              transitive_defeats << [ cand2, cand3 ]
+          unless cand1 == cand2
+            candidates.each do |cand3|
+              if not cand2 == cand3 and 
+                  not cand1 == cand3 and 
+                  transitive_defeats.include?( [ cand2, cand1 ] ) and
+                  transitive_defeats.include?( [ cand1, cand3 ] ) and
+                  not transitive_defeats.include?( [ cand2, cand3 ] )
+                transitive_defeats << [ cand2, cand3 ]
+              end
             end
           end
         end

Benjamin Mako Hill || Want to submit a patch?