Implement benders decomposition algorithm for rectangle

data/rectangle/tests/knapsack_benders_all_fit_bins.csv

@@ -0,0 +1,2 @@
+ID,WIDTH,HEIGHT
+0,20,10

data/rectangle/tests/knapsack_benders_all_fit_items.csv

@@ -0,0 +1,6 @@
+ID,WIDTH,HEIGHT,ORIENTED,COPIES
+0,12,6,1,1
+1,8,3,1,1
+2,16,4,1,1
+3,4,7,1,1
+4,4,3,1,1

data/rectangle/tests/knapsack_benders_all_fit_parameters.csv

@@ -0,0 +1,2 @@
+NAME,VALUE
+objective,knapsack

data/rectangle/tests/knapsack_benders_all_fit_solution.csv

@@ -0,0 +1,7 @@
+TYPE,ID,COPIES,BIN,X,Y,LX,LY
+BIN,0,1,0,0,0,20,10
+ITEM,0,1,0,0,0,12,6
+ITEM,2,1,0,0,6,16,4
+ITEM,1,1,0,12,0,8,3
+ITEM,4,1,0,12,3,4,3
+ITEM,3,1,0,16,3,4,7

data/rectangle/tests/knapsack_benders_incompatible_pairs_bins.csv

@@ -0,0 +1,2 @@
+ID,WIDTH,HEIGHT
+1,20,10

data/rectangle/tests/knapsack_benders_incompatible_pairs_items.csv

@@ -0,0 +1,3 @@
+ID,WIDTH,HEIGHT,ORIENTED,COPIES,PROFIT
+0,10,5,1,4,50
+1,11,6,1,1,190

data/rectangle/tests/knapsack_benders_incompatible_pairs_parameters.csv

@@ -0,0 +1,2 @@
+NAME,VALUE
+objective,knapsack

data/rectangle/tests/knapsack_benders_incompatible_pairs_solution.csv

@@ -0,0 +1,6 @@
+TYPE,ID,COPIES,BIN,X,Y,LX,LY
+BIN,0,1,0,0,0,20,10
+ITEM,0,1,0,0,0,10,5
+ITEM,0,1,0,0,5,10,5
+ITEM,0,1,0,10,0,10,5
+ITEM,0,1,0,10,5,10,5

data/rectangle/tests/knapsack_benders_unpacked_high_profit_bins.csv

@@ -0,0 +1,2 @@
+ID,WIDTH,HEIGHT
+1,24,18

data/rectangle/tests/knapsack_benders_unpacked_high_profit_items.csv

@@ -0,0 +1,3 @@
+ID,WIDTH,HEIGHT,ORIENTED,COPIES,PROFIT
+0,8,6,1,9,50
+1,9,7,1,1,199

data/rectangle/tests/knapsack_benders_unpacked_high_profit_parameters.csv

@@ -0,0 +1,2 @@
+NAME,VALUE
+objective,knapsack

data/rectangle/tests/knapsack_benders_unpacked_high_profit_solution.csv

@@ -0,0 +1,11 @@
+TYPE,ID,COPIES,BIN,X,Y,LX,LY
+BIN,0,1,0,0,0,24,18
+ITEM,0,1,0,0,0,8,6
+ITEM,0,1,0,0,6,8,6
+ITEM,0,1,0,0,12,8,6
+ITEM,0,1,0,8,0,8,6
+ITEM,0,1,0,8,6,8,6
+ITEM,0,1,0,8,12,8,6
+ITEM,0,1,0,16,0,8,6
+ITEM,0,1,0,16,6,8,6
+ITEM,0,1,0,16,12,8,6

extern/CMakeLists.txt

@@ -20,6 +20,14 @@ FetchContent_Declare(
     EXCLUDE_FROM_ALL)
 FetchContent_MakeAvailable(mathoptsolverscmake)
 
+# Fetch Highs.
+set(BUILD_SHARED_LIBS OFF)
+FetchContent_Declare(
+    highs
+    URL https://github.com/ERGO-Code/HiGHS/archive/refs/tags/v1.7.2.zip
+    EXCLUDE_FROM_ALL)
+FetchContent_MakeAvailable(highs)
+
 # Fetch boost.
 set(BOOST_INCLUDE_LIBRARIES thread filesystem system program_options dynamic_bitset)
 set(BOOST_ENABLE_CMAKE ON)

include/packingsolver/rectangle/instance.hpp

@@ -51,6 +51,9 @@ struct Rectangle
 
     /** Get the legnth of the largest side of the rectangle. */
     Length max() const { return std::max(x, y); }
+
+    /** Get the legnth of the largest side of the rectangle. */
+    Length min() const { return std::min(x, y); }
 };
 
 bool rect_intersection(Point c1, Rectangle r1, Point c2, Rectangle r2);

include/packingsolver/rectangle/optimize.hpp

@@ -42,6 +42,9 @@ struct OptimizeParameters: packingsolver::Parameters<Instance, Solution>
     /** Use column generation algorithm. */
     bool use_column_generation = false;
 
+    /** Use Benders decomposition algorithm. */
+    bool use_benders_decomposition = false;
+
     /** Guides used in the tree search algorithm. */
     std::vector<GuideId> tree_search_guides;
 
@@ -63,6 +66,12 @@ struct OptimizeParameters: packingsolver::Parameters<Instance, Solution>
      */
     NodeId column_generation_subproblem_queue_size = 128;
 
+    /**
+     * Size of the queue for the pricing knapsack subproblem of the Benders
+     * decomposition algorithm.
+     */
+    NodeId benders_decomposition_subproblem_queue_size = 128;
+
     /*
      * Parameters for non-anytime mode
      */
@@ -79,6 +88,9 @@ struct OptimizeParameters: packingsolver::Parameters<Instance, Solution>
     /** Number of iterations of the sequential value correction algorithm. */
     Counter not_anytime_sequential_value_correction_number_of_iterations = 32;
 
+    /** Number of iterations of the Benders decomposition algorithm. */
+    Counter not_anytime_benders_decomposition_number_of_iterations = 32;
+
     /**
      * Size of the queue in the bin packing subproblem of the dichotomic search
      * algorithm.

src/rectangle/CMakeLists.txt

@@ -7,14 +7,16 @@ target_sources(PackingSolver_rectangle PRIVATE
     instance_flipper.cpp
     algorithm_formatter.cpp
     optimize.cpp
-    branching_scheme.cpp)
+    branching_scheme.cpp
+    benders_decomposition.cpp)
 target_include_directories(PackingSolver_rectangle PUBLIC
     ${PROJECT_SOURCE_DIR}/include)
 target_include_directories(PackingSolver_rectangle PRIVATE
     ${PROJECT_SOURCE_DIR}/src)
 target_link_libraries(PackingSolver_rectangle PUBLIC
     PackingSolver_algorithms
     TreeSearchSolver::treesearchsolver
+    highs
     Threads::Threads)
 add_library(PackingSolver::rectangle ALIAS PackingSolver_rectangle)