72 lines
1.7 KiB
Ruby
72 lines
1.7 KiB
Ruby
# Copyright (C) 2024-2025 LibreWeddingPlanner contributors
|
|
|
|
# frozen_string_literal: true
|
|
|
|
module VNS
|
|
class Engine
|
|
class << self
|
|
def sequence(elements)
|
|
elements = elements.to_a
|
|
(elements + elements.reverse).chunk(&:itself).map(&:first)
|
|
end
|
|
end
|
|
|
|
def target_function(&function)
|
|
@target_function = function
|
|
end
|
|
|
|
def add_optimization(klass)
|
|
@optimizations ||= Set.new
|
|
@optimizations << klass
|
|
end
|
|
|
|
def add_perturbation(klass)
|
|
@perturbations ||= Set.new
|
|
@perturbations << klass
|
|
end
|
|
|
|
attr_writer :initial_solution
|
|
|
|
def run
|
|
raise 'No target function defined' unless @target_function
|
|
raise 'No optimizations defined' unless @optimizations
|
|
raise 'No initial solution defined' unless @initial_solution
|
|
|
|
@perturbations ||= Set.new
|
|
|
|
@best_solution = @initial_solution
|
|
@best_score = @target_function.call(@best_solution)
|
|
|
|
self.class.sequence(@optimizations).each do |optimization|
|
|
optimize(optimization)
|
|
Rails.logger.debug { "Finished optimization phase: #{optimization.name}" }
|
|
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|
|
|
score = @target_function.call(alternative_solution)
|
|
next if score >= @best_score
|
|
|
|
@best_solution = alternative_solution.deep_dup
|
|
@best_score = score
|
|
optimized = true
|
|
|
|
break
|
|
end
|
|
|
|
return unless optimized
|
|
end
|
|
end
|
|
end
|
|
end
|