Solution ruin steps

libvroom_examples/libvroom.cpp

@@ -218,11 +218,11 @@ void run_example_with_osrm() {
   // - jobs 3 and 4 can only be served by vehicle 2
   // - jobs 5 and 6 can be served by either one of the vehicles
 
-  // Solve!
+  // Solve using exploration level as depth and number of searches.
   auto sol =
-    problem_instance.solve(vroom::DEFAULT_EXPLORATION_LEVEL, // Exploration
-                                                             // level.
-                           vroom::DEFAULT_THREADS_NUMBER);   // Use 4 threads.
+    problem_instance.solve(vroom::DEFAULT_EXPLORATION_LEVEL,
+                           vroom::DEFAULT_EXPLORATION_LEVEL,
+                           vroom::DEFAULT_THREADS_NUMBER); // Use 4 threads.
 
   log_solution(sol, GEOMETRY);
 }
@@ -274,11 +274,11 @@ void run_example_with_custom_matrix() {
     problem_instance.add_job(j);
   }
 
-  // Solve!
+  // Solve using exploration level as depth and number of searches.
   auto sol =
-    problem_instance.solve(vroom::DEFAULT_EXPLORATION_LEVEL, // Exploration
-                                                             // level.
-                           vroom::DEFAULT_THREADS_NUMBER);   // Use 4 threads.
+    problem_instance.solve(vroom::DEFAULT_EXPLORATION_LEVEL,
+                           vroom::DEFAULT_EXPLORATION_LEVEL,
+                           vroom::DEFAULT_THREADS_NUMBER); // Use 4 threads.
 
   log_solution(sol, GEOMETRY);
 }

src/algorithms/local_search/local_search.cpp

@@ -75,11 +75,11 @@ LocalSearch<Route,
             PriorityReplace,
             TSPFix>::LocalSearch(const Input& input,
                                  std::vector<Route>& sol,
-                                 unsigned max_nb_jobs_removal,
+                                 unsigned depth,
                                  const Timeout& timeout)
   : _input(input),
     _nb_vehicles(_input.vehicles.size()),
-    _max_nb_jobs_removal(max_nb_jobs_removal),
+    _depth(depth),
     _deadline(timeout.has_value() ? utils::now() + timeout.value()
                                   : Deadline()),
     _all_routes(_nb_vehicles),
@@ -162,7 +162,12 @@ void LocalSearch<Route,
                  RouteSplit,
                  PriorityReplace,
                  TSPFix>::try_job_additions(const std::vector<Index>& routes,
-                                            double regret_coeff) {
+                                            double regret_coeff
+#ifdef LOG_LS
+                                            ,
+                                            bool log_addition_step
+#endif
+) {
   bool job_added;
 
   std::vector<std::vector<RouteInsertion>> route_job_insertions;
@@ -318,6 +323,16 @@ void LocalSearch<Route,
           route_job_insertions[best_route_idx][j].eval.cost += fixed_cost;
         }
       }
+
+#ifdef LOG_LS
+      if (log_addition_step) {
+        steps.push_back({utils::now(),
+                         log::EVENT::JOB_ADDITION,
+                         OperatorName::MAX,
+                         utils::SolutionIndicators<Route>(_input, _sol),
+                         std::nullopt});
+      }
+#endif
     }
   } while (job_added);
 
@@ -1830,6 +1845,14 @@ void LocalSearch<Route,
       ++applied_moves.at(best_ops[best_source][best_target]->get_name());
 #endif
 
+#ifdef LOG_LS
+      steps.push_back({utils::now(),
+                       log::EVENT::OPERATOR,
+                       best_ops[best_source][best_target]->get_name(),
+                       utils::SolutionIndicators<Route>(_input, _sol),
+                       std::nullopt});
+#endif
+
 #ifndef NDEBUG
       // Update route costs.
       const auto previous_eval =
@@ -1869,7 +1892,12 @@ void LocalSearch<Route,
 
       try_job_additions(best_ops[best_source][best_target]
                           ->addition_candidates(),
-                        0);
+                        0
+#ifdef LOG_LS
+                        ,
+                        true
+#endif
+      );
 
       for (auto v_rank : update_candidates) {
         _sol_state.update_costs(_sol[v_rank].route, v_rank);
@@ -1982,6 +2010,14 @@ void LocalSearch<Route,
 
   unsigned current_nb_removal = 1;
 
+#ifdef LOG_LS
+  steps.push_back({utils::now(),
+                   log::EVENT::START,
+                   OperatorName::MAX,
+                   _best_sol_indicators,
+                   utils::format_solution(_input, _best_sol)});
+#endif
+
   while (try_ls_step) {
     // A round of local search.
     run_ls_step();
@@ -1992,6 +2028,14 @@ void LocalSearch<Route,
         current_sol_indicators < _best_sol_indicators) {
       _best_sol_indicators = current_sol_indicators;
       _best_sol = _sol;
+
+#ifdef LOG_LS
+      steps.push_back({utils::now(),
+                       log::EVENT::LOCAL_MINIMA,
+                       OperatorName::MAX,
+                       _best_sol_indicators,
+                       utils::format_solution(_input, _best_sol)});
+#endif
     } else {
       if (!first_step) {
         ++current_nb_removal;
@@ -2001,11 +2045,21 @@ void LocalSearch<Route,
         _sol = _best_sol;
         _sol_state.setup(_sol);
       }
+#ifdef LOG_LS
+      if (_best_sol_indicators < current_sol_indicators or
+          _best_sol_indicators == current_sol_indicators) {
+        steps.push_back({utils::now(),
+                         log::EVENT::ROLLBACK,
+                         OperatorName::MAX,
+                         _best_sol_indicators,
+                         std::nullopt});
+      }
+#endif
     }
 
     // Try again on each improvement until we reach last job removal
     // level or deadline is met.
-    try_ls_step = (current_nb_removal <= _max_nb_jobs_removal) &&
+    try_ls_step = (current_nb_removal <= _depth) &&
                   (!_deadline.has_value() || utils::now() < _deadline.value());
 
     if (try_ls_step) {
@@ -2023,6 +2077,14 @@ void LocalSearch<Route,
         }
       }
 
+#ifdef LOG_LS
+      steps.push_back({utils::now(),
+                       log::EVENT::RUIN,
+                       OperatorName::MAX,
+                       utils::SolutionIndicators<Route>(_input, _sol),
+                       utils::format_solution(_input, _sol)});
+#endif
+
       // Update insertion ranks ranges.
       for (std::size_t v = 0; v < _sol.size(); ++v) {
         _sol_state.set_insertion_ranks(_sol[v], v);
@@ -2043,6 +2105,14 @@ void LocalSearch<Route,
         _sol_state.set_pd_matching_ranks(_sol[v].route, v);
         _sol_state.set_pd_gains(_sol[v].route, v);
       }
+
+#ifdef LOG_LS
+      steps.push_back({utils::now(),
+                       log::EVENT::RECREATE,
+                       OperatorName::MAX,
+                       utils::SolutionIndicators<Route>(_input, _sol),
+                       utils::format_solution(_input, _sol)});
+#endif
     }
 
     first_step = false;

src/algorithms/local_search/local_search.h

@@ -13,6 +13,10 @@ All rights reserved (see LICENSE).
 #include "structures/vroom/solution_indicators.h"
 #include "structures/vroom/solution_state.h"
 
+#ifdef LOG_LS
+#include "algorithms/local_search/log_local_search.h"
+#endif
+
 namespace vroom::ls {
 
 template <class Route,
@@ -40,7 +44,7 @@ class LocalSearch {
   const Input& _input;
   const std::size_t _nb_vehicles;
 
-  const unsigned _max_nb_jobs_removal;
+  const unsigned _depth;
   const Deadline _deadline;
 
   std::vector<Index> _all_routes;
@@ -58,7 +62,17 @@ class LocalSearch {
   std::array<unsigned, OperatorName::MAX> applied_moves;
 #endif
 
-  void try_job_additions(const std::vector<Index>& routes, double regret_coeff);
+#ifdef LOG_LS
+  std::vector<log::Step<Route>> steps;
+#endif
+
+  void try_job_additions(const std::vector<Index>& routes,
+                         double regret_coeff
+#ifdef LOG_LS
+                         ,
+                         bool log_addition_step = false
+#endif
+  );
 
   void run_ls_step();
 
@@ -78,7 +92,7 @@ class LocalSearch {
 public:
   LocalSearch(const Input& input,
               std::vector<Route>& tw_sol,
-              unsigned max_nb_jobs_removal,
+              unsigned depth,
               const Timeout& timeout);
 
   utils::SolutionIndicators<Route> indicators() const;
@@ -88,6 +102,12 @@ class LocalSearch {
 #ifdef LOG_LS_OPERATORS
   std::array<OperatorStats, OperatorName::MAX> get_stats() const;
 #endif
+
+#ifdef LOG_LS
+  std::vector<log::Step<Route>> get_steps() {
+    return steps;
+  }
+#endif
 };
 
 } // namespace vroom::ls

src/algorithms/local_search/log_local_search.h

@@ -0,0 +1,42 @@
+#ifndef LOG_LOCAL_SEARCH_H
+#define LOG_LOCAL_SEARCH_H
+
+/*
+
+This file is part of VROOM.
+
+Copyright (c) 2015-2024, Julien Coupey.
+All rights reserved (see LICENSE).
+
+*/
+
+#include "structures/vroom/solution/solution.h"
+#include "structures/vroom/solution_indicators.h"
+
+namespace vroom::ls::log {
+
+enum class EVENT {
+  START,
+  OPERATOR,
+  LOCAL_MINIMA,
+  JOB_ADDITION,
+  RUIN,
+  RECREATE,
+  ROLLBACK
+};
+
+template <class Route> struct Step {
+  TimePoint time_point;
+  EVENT event;
+  OperatorName operator_name;
+  vroom::utils::SolutionIndicators<Route> indicators;
+  std::optional<Solution> solution;
+};
+
+template <class Route> struct Dump {
+  HeuristicParameters heuristic_parameters;
+  std::vector<Step<Route>> steps;
+};
+} // namespace vroom::ls::log
+
+#endif

src/main.cpp

@@ -33,6 +33,7 @@ int main(int argc, char** argv) {
   std::string limit_arg;
   std::string output_file;
   std::vector<std::string> heuristic_params_arg;
+  unsigned exploration_level;
 
   cxxopts::Options options("vroom",
                            "VROOM Copyright (C) 2015-2024, Julien Coupey\n"
@@ -79,19 +80,28 @@ int main(int argc, char** argv) {
     ("v,version", "output version information and exit")
     ("x,explore",
      "exploration level to use (0..5)",
-     cxxopts::value<unsigned>(cl_args.exploration_level)->default_value(std::to_string(vroom::DEFAULT_EXPLORATION_LEVEL)))
+     cxxopts::value<unsigned>(exploration_level)->default_value(std::to_string(vroom::DEFAULT_EXPLORATION_LEVEL)))
     ("stdin",
      "optional input positional arg",
      cxxopts::value<std::string>(cl_args.input));
 
   // we don't want to print debug args on --help
+  std::optional<unsigned> debug_depth;
+  std::optional<unsigned> debug_nb_searches;
+
   options.add_options("debug_group")
     ("e,heuristic-param",
      "Heuristic parameter",
      cxxopts::value<std::vector<std::string>>(heuristic_params_arg))
     ("f,apply-tsp-fix",
      "apply experimental TSPFix local search operator",
-     cxxopts::value<bool>(cl_args.apply_TSPFix)->default_value("false"));
+     cxxopts::value<bool>(cl_args.apply_TSPFix)->default_value("false"))
+    ("d,depth",
+     "search depth",
+     cxxopts::value<std::optional<unsigned>>(debug_depth))
+    ("s,nb-searches",
+     "number of searches to perform in parallel",
+     cxxopts::value<std::optional<unsigned>>(debug_nb_searches));
 
   // clang-format on
   try {
@@ -153,8 +163,14 @@ int main(int argc, char** argv) {
   for (const auto& port : port_args) {
     vroom::io::update_port(cl_args.servers, port);
   }
-  cl_args.exploration_level =
-    std::min(cl_args.exploration_level, vroom::MAX_EXPLORATION_LEVEL);
+  exploration_level = std::min(exploration_level, vroom::MAX_EXPLORATION_LEVEL);
+  vroom::io::set_exploration_level(cl_args, exploration_level);
+  if (debug_depth) {
+    cl_args.depth = debug_depth.value();
+  }
+  if (debug_nb_searches) {
+    cl_args.nb_searches = debug_nb_searches.value();
+  }
 
   // Determine routing engine (defaults to ROUTER::OSRM).
   if (router_arg == "libosrm") {
@@ -220,7 +236,8 @@ int main(int argc, char** argv) {
 
     vroom::Solution sol = (cl_args.check)
                             ? problem_instance.check(cl_args.nb_threads)
-                            : problem_instance.solve(cl_args.exploration_level,
+                            : problem_instance.solve(cl_args.nb_searches,
+                                                     cl_args.depth,
                                                      cl_args.nb_threads,
                                                      cl_args.timeout,
                                                      cl_args.h_params);

src/makefile

@@ -6,7 +6,7 @@
 # Variables.
 CXX ?= g++
 USE_ROUTING ?= true
-CXXFLAGS = -MMD -MP -I. -std=c++20 -Wextra -Wpedantic -Wall -O3 -DASIO_STANDALONE -DUSE_ROUTING=$(USE_ROUTING)
+CXXFLAGS = -MMD -MP -I. -std=c++20 -Wextra -Wpedantic -Wall -O3 -DASIO_STANDALONE -DUSE_ROUTING=$(USE_ROUTING) -DLOG_LS
 LDLIBS = -lpthread
 
 # Using all cpp files in current directory.

src/problems/cvrp/cvrp.cpp

@@ -143,7 +143,8 @@ const std::vector<HeuristicParameters> CVRP::heterogeneous_parameters =
 CVRP::CVRP(const Input& input) : VRP(input) {
 }
 
-Solution CVRP::solve(unsigned exploration_level,
+Solution CVRP::solve(unsigned nb_searches,
+                     unsigned depth,
                      unsigned nb_threads,
                      const Timeout& timeout,
                      const std::vector<HeuristicParameters>& h_param) const {
@@ -164,7 +165,8 @@ Solution CVRP::solve(unsigned exploration_level,
     return utils::format_solution(_input, {r});
   }
 
-  return VRP::solve<RawRoute, cvrp::LocalSearch>(exploration_level,
+  return VRP::solve<RawRoute, cvrp::LocalSearch>(nb_searches,
+                                                 depth,
                                                  nb_threads,
                                                  timeout,
                                                  h_param,

src/problems/cvrp/cvrp.h

@@ -25,7 +25,8 @@ class CVRP : public VRP {
   explicit CVRP(const Input& input);
 
   Solution
-  solve(unsigned exploration_level,
+  solve(unsigned nb_searches,
+        unsigned depth,
         unsigned nb_threads,
         const Timeout& timeout,
         const std::vector<HeuristicParameters>& h_param) const override;