Run perturbation on top of the best solution so far

app/services/vns/engine.rb

@@ -34,30 +34,49 @@ module VNS
 
       @perturbations ||= Set.new
 
-      @best_solution = @initial_solution
-      @best_score = @target_function.call(@best_solution)
+      @current_solution = @initial_solution
+      @best_score = @target_function.call(@current_solution)
 
+      run_all_optimizations
+
+      best_solution = @current_solution
+
+      50.times do
+        @current_solution = Tables::WheelSwap.new(best_solution).call
+        @best_score = @target_function.call(@current_solution)
+        Rails.logger.debug { "After perturbation: #{@best_score}" }
+
+        run_all_optimizations
+
+        if best_solution.discomfort > @current_solution.discomfort
+          best_solution = @current_solution 
+          Rails.logger.debug { "Found better solution after perturbation optimization: #{@current_solution.discomfort}" }
+        end
+      end
+
+
+      best_solution
+    end
+
+    private
+
+    def run_all_optimizations
       self.class.sequence(@optimizations).each do |optimization|
         optimize(optimization)
         Rails.logger.debug { "Finished optimization phase: #{optimization}" }
       end
-
       Rails.logger.debug { "Finished all optimization phases" }
-
-      @best_solution
     end
 
-    private
-
     def optimize(optimization_klass)
       loop do
         optimized = false
 
-        optimization_klass.new(@best_solution).each do |alternative_solution|
+        optimization_klass.new(@current_solution).each do |alternative_solution|
           score = @target_function.call(alternative_solution)
           next if score >= @best_score
 
-          @best_solution = alternative_solution.deep_dup
+          @current_solution = alternative_solution.deep_dup
           @best_score = score
           optimized = true
           Rails.logger.debug { "[#{optimization_klass}] Found better solution with score: #{score}" }