Reduce the swap candidates per table to one per group

app/services/tables/swap.rb

@@ -7,7 +7,7 @@ module Tables
 
     def each
       @initial_solution.tables.combination(2) do |table_a, table_b|
-        table_a.product(table_b).each do |(person_a, person_b)|
+        table_a.swap_candidates.product(table_b.swap_candidates).each do |(person_a, person_b)|
           new_solution = @initial_solution.dup
 
           new_table_a = table_a.dup

app/services/tables/table.rb

@@ -5,20 +5,17 @@ module Tables
 
     def initialize(*args)
       super
-      reset
       @id = SecureRandom.uuid
     end
 
-    def reset
-      original_discomfort = @discomfort
-      @discomfort = nil
-      original_discomfort
-    end
-
     def discomfort
       @discomfort ||= DiscomfortCalculator.new(self).calculate
     end
 
+    def swap_candidates
+      @swap_candidates ||= uniq { |person| person.affinity_group_list.first }
+    end
+
     def dup
       super.tap do |new_table|
         new_table.discomfort = nil