Merge pull request 'Avoid stack too deep erros due to excessive recursion' (#178) from stack-error-vns into main

Reviewed-on: #178

app/services/vns/engine.rb

@@ -29,7 +29,7 @@ module VNS
       @best_score = @target_function.call(@best_solution)
 
       self.class.sequence(@perturbations).each do |perturbation|
-        optimize(perturbation.new(@best_solution))
+        optimize(perturbation)
       end
 
       @best_solution
@@ -37,15 +37,22 @@ module VNS
 
     private
 
-    def optimize(perturbation)
-      perturbation.each do |alternative_solution|
-        score = @target_function.call(alternative_solution)
-        next if score >= @best_score
+    def optimize(perturbation_klass)
+      loop do
+        optimized = false
 
-        @best_solution = alternative_solution.deep_dup
-        @best_score = score
+        perturbation_klass.new(@best_solution).each do |alternative_solution|
+          score = @target_function.call(alternative_solution)
+          next if score >= @best_score
 
-        return optimize(perturbation.class.new(@best_solution))
+          @best_solution = alternative_solution.deep_dup
+          @best_score = score
+          optimized = true
+
+          break
+        end
+
+        return unless optimized
       end
     end
   end