| // Copyright Michael Drexl 2005, 2006. |
| // Distributed under the Boost Software License, Version 1.0. |
| // (See accompanying file LICENSE_1_0.txt or copy at |
| // http://boost.org/LICENSE_1_0.txt) |
| |
| // Example use of the resource-constrained shortest paths algorithm. |
| #include <boost/config.hpp> |
| |
| #ifdef BOOST_MSVC |
| # pragma warning(disable: 4267) |
| #endif |
| |
| #include <boost/graph/adjacency_list.hpp> |
| |
| #include <boost/graph/r_c_shortest_paths.hpp> |
| #include <iostream> |
| |
| using namespace boost; |
| |
| struct SPPRC_Example_Graph_Vert_Prop |
| { |
| SPPRC_Example_Graph_Vert_Prop( int n = 0, int e = 0, int l = 0 ) |
| : num( n ), eat( e ), lat( l ) {} |
| int num; |
| // earliest arrival time |
| int eat; |
| // latest arrival time |
| int lat; |
| }; |
| |
| struct SPPRC_Example_Graph_Arc_Prop |
| { |
| SPPRC_Example_Graph_Arc_Prop( int n = 0, int c = 0, int t = 0 ) |
| : num( n ), cost( c ), time( t ) {} |
| int num; |
| // traversal cost |
| int cost; |
| // traversal time |
| int time; |
| }; |
| |
| typedef adjacency_list<vecS, |
| vecS, |
| directedS, |
| SPPRC_Example_Graph_Vert_Prop, |
| SPPRC_Example_Graph_Arc_Prop> |
| SPPRC_Example_Graph; |
| |
| // data structures for spp without resource constraints: |
| // ResourceContainer model |
| struct spp_no_rc_res_cont |
| { |
| spp_no_rc_res_cont( int c = 0 ) : cost( c ) {}; |
| spp_no_rc_res_cont& operator=( const spp_no_rc_res_cont& other ) |
| { |
| if( this == &other ) |
| return *this; |
| this->~spp_no_rc_res_cont(); |
| new( this ) spp_no_rc_res_cont( other ); |
| return *this; |
| } |
| int cost; |
| }; |
| |
| bool operator==( const spp_no_rc_res_cont& res_cont_1, |
| const spp_no_rc_res_cont& res_cont_2 ) |
| { |
| return ( res_cont_1.cost == res_cont_2.cost ); |
| } |
| |
| bool operator<( const spp_no_rc_res_cont& res_cont_1, |
| const spp_no_rc_res_cont& res_cont_2 ) |
| { |
| return ( res_cont_1.cost < res_cont_2.cost ); |
| } |
| |
| // ResourceExtensionFunction model |
| class ref_no_res_cont |
| { |
| public: |
| inline bool operator()( const SPPRC_Example_Graph& g, |
| spp_no_rc_res_cont& new_cont, |
| const spp_no_rc_res_cont& old_cont, |
| graph_traits |
| <SPPRC_Example_Graph>::edge_descriptor ed ) const |
| { |
| new_cont.cost = old_cont.cost + g[ed].cost; |
| return true; |
| } |
| }; |
| |
| // DominanceFunction model |
| class dominance_no_res_cont |
| { |
| public: |
| inline bool operator()( const spp_no_rc_res_cont& res_cont_1, |
| const spp_no_rc_res_cont& res_cont_2 ) const |
| { |
| // must be "<=" here!!! |
| // must NOT be "<"!!! |
| return res_cont_1.cost <= res_cont_2.cost; |
| // this is not a contradiction to the documentation |
| // the documentation says: |
| // "A label $l_1$ dominates a label $l_2$ if and only if both are resident |
| // at the same vertex, and if, for each resource, the resource consumption |
| // of $l_1$ is less than or equal to the resource consumption of $l_2$, |
| // and if there is at least one resource where $l_1$ has a lower resource |
| // consumption than $l_2$." |
| // one can think of a new label with a resource consumption equal to that |
| // of an old label as being dominated by that old label, because the new |
| // one will have a higher number and is created at a later point in time, |
| // so one can implicitly use the number or the creation time as a resource |
| // for tie-breaking |
| } |
| }; |
| // end data structures for spp without resource constraints: |
| |
| // data structures for shortest path problem with time windows (spptw) |
| // ResourceContainer model |
| struct spp_spptw_res_cont |
| { |
| spp_spptw_res_cont( int c = 0, int t = 0 ) : cost( c ), time( t ) {} |
| spp_spptw_res_cont& operator=( const spp_spptw_res_cont& other ) |
| { |
| if( this == &other ) |
| return *this; |
| this->~spp_spptw_res_cont(); |
| new( this ) spp_spptw_res_cont( other ); |
| return *this; |
| } |
| int cost; |
| int time; |
| }; |
| |
| bool operator==( const spp_spptw_res_cont& res_cont_1, |
| const spp_spptw_res_cont& res_cont_2 ) |
| { |
| return ( res_cont_1.cost == res_cont_2.cost |
| && res_cont_1.time == res_cont_2.time ); |
| } |
| |
| bool operator<( const spp_spptw_res_cont& res_cont_1, |
| const spp_spptw_res_cont& res_cont_2 ) |
| { |
| if( res_cont_1.cost > res_cont_2.cost ) |
| return false; |
| if( res_cont_1.cost == res_cont_2.cost ) |
| return res_cont_1.time < res_cont_2.time; |
| return true; |
| } |
| |
| // ResourceExtensionFunction model |
| class ref_spptw |
| { |
| public: |
| inline bool operator()( const SPPRC_Example_Graph& g, |
| spp_spptw_res_cont& new_cont, |
| const spp_spptw_res_cont& old_cont, |
| graph_traits |
| <SPPRC_Example_Graph>::edge_descriptor ed ) const |
| { |
| const SPPRC_Example_Graph_Arc_Prop& arc_prop = |
| get( edge_bundle, g )[ed]; |
| const SPPRC_Example_Graph_Vert_Prop& vert_prop = |
| get( vertex_bundle, g )[target( ed, g )]; |
| new_cont.cost = old_cont.cost + arc_prop.cost; |
| int& i_time = new_cont.time; |
| i_time = old_cont.time + arc_prop.time; |
| i_time < vert_prop.eat ? i_time = vert_prop.eat : 0; |
| return i_time <= vert_prop.lat ? true : false; |
| } |
| }; |
| |
| // DominanceFunction model |
| class dominance_spptw |
| { |
| public: |
| inline bool operator()( const spp_spptw_res_cont& res_cont_1, |
| const spp_spptw_res_cont& res_cont_2 ) const |
| { |
| // must be "<=" here!!! |
| // must NOT be "<"!!! |
| return res_cont_1.cost <= res_cont_2.cost |
| && res_cont_1.time <= res_cont_2.time; |
| // this is not a contradiction to the documentation |
| // the documentation says: |
| // "A label $l_1$ dominates a label $l_2$ if and only if both are resident |
| // at the same vertex, and if, for each resource, the resource consumption |
| // of $l_1$ is less than or equal to the resource consumption of $l_2$, |
| // and if there is at least one resource where $l_1$ has a lower resource |
| // consumption than $l_2$." |
| // one can think of a new label with a resource consumption equal to that |
| // of an old label as being dominated by that old label, because the new |
| // one will have a higher number and is created at a later point in time, |
| // so one can implicitly use the number or the creation time as a resource |
| // for tie-breaking |
| } |
| }; |
| // end data structures for shortest path problem with time windows (spptw) |
| |
| // example graph structure and cost from |
| // http://www.boost.org/libs/graph/example/dijkstra-example.cpp |
| const int num_nodes = 5; |
| enum nodes { A, B, C, D, E }; |
| char name[] = "ABCDE"; |
| |
| int main() |
| { |
| SPPRC_Example_Graph g; |
| |
| add_vertex( SPPRC_Example_Graph_Vert_Prop( A, 0, 0 ), g ); |
| add_vertex( SPPRC_Example_Graph_Vert_Prop( B, 5, 20 ), g ); |
| add_vertex( SPPRC_Example_Graph_Vert_Prop( C, 6, 10 ), g ); |
| add_vertex( SPPRC_Example_Graph_Vert_Prop( D, 3, 12 ), g ); |
| add_vertex( SPPRC_Example_Graph_Vert_Prop( E, 0, 100 ), g ); |
| |
| add_edge( A, C, SPPRC_Example_Graph_Arc_Prop( 0, 1, 5 ), g ); |
| add_edge( B, B, SPPRC_Example_Graph_Arc_Prop( 1, 2, 5 ), g ); |
| add_edge( B, D, SPPRC_Example_Graph_Arc_Prop( 2, 1, 2 ), g ); |
| add_edge( B, E, SPPRC_Example_Graph_Arc_Prop( 3, 2, 7 ), g ); |
| add_edge( C, B, SPPRC_Example_Graph_Arc_Prop( 4, 7, 3 ), g ); |
| add_edge( C, D, SPPRC_Example_Graph_Arc_Prop( 5, 3, 8 ), g ); |
| add_edge( D, E, SPPRC_Example_Graph_Arc_Prop( 6, 1, 3 ), g ); |
| add_edge( E, A, SPPRC_Example_Graph_Arc_Prop( 7, 1, 5 ), g ); |
| add_edge( E, B, SPPRC_Example_Graph_Arc_Prop( 8, 1, 4 ), g ); |
| |
| |
| // the unique shortest path from A to E in the dijkstra-example.cpp is |
| // A -> C -> D -> E |
| // its length is 5 |
| // the following code also yields this result |
| |
| // with the above time windows, this path is infeasible |
| // now, there are two shortest paths that are also feasible with respect to |
| // the vertex time windows: |
| // A -> C -> B -> D -> E and |
| // A -> C -> B -> E |
| // however, the latter has a longer total travel time and is therefore not |
| // pareto-optimal, i.e., it is dominated by the former path |
| // therefore, the code below returns only the former path |
| |
| // spp without resource constraints |
| graph_traits<SPPRC_Example_Graph>::vertex_descriptor s = A; |
| graph_traits<SPPRC_Example_Graph>::vertex_descriptor t = E; |
| |
| std::vector |
| <std::vector |
| <graph_traits<SPPRC_Example_Graph>::edge_descriptor> > |
| opt_solutions; |
| std::vector<spp_no_rc_res_cont> pareto_opt_rcs_no_rc; |
| |
| r_c_shortest_paths |
| ( g, |
| get( &SPPRC_Example_Graph_Vert_Prop::num, g ), |
| get( &SPPRC_Example_Graph_Arc_Prop::num, g ), |
| s, |
| t, |
| opt_solutions, |
| pareto_opt_rcs_no_rc, |
| spp_no_rc_res_cont( 0 ), |
| ref_no_res_cont(), |
| dominance_no_res_cont(), |
| std::allocator |
| <r_c_shortest_paths_label |
| <SPPRC_Example_Graph, spp_no_rc_res_cont> >(), |
| default_r_c_shortest_paths_visitor() ); |
| |
| std::cout << "SPP without resource constraints:" << std::endl; |
| std::cout << "Number of optimal solutions: "; |
| std::cout << static_cast<int>( opt_solutions.size() ) << std::endl; |
| for( int i = 0; i < static_cast<int>( opt_solutions.size() ); ++i ) |
| { |
| std::cout << "The " << i << "th shortest path from A to E is: "; |
| std::cout << std::endl; |
| for( int j = static_cast<int>( opt_solutions[i].size() ) - 1; j >= 0; --j ) |
| std::cout << name[source( opt_solutions[i][j], g )] << std::endl; |
| std::cout << "E" << std::endl; |
| std::cout << "Length: " << pareto_opt_rcs_no_rc[i].cost << std::endl; |
| } |
| std::cout << std::endl; |
| |
| // spptw |
| std::vector |
| <std::vector |
| <graph_traits<SPPRC_Example_Graph>::edge_descriptor> > |
| opt_solutions_spptw; |
| std::vector<spp_spptw_res_cont> pareto_opt_rcs_spptw; |
| |
| r_c_shortest_paths |
| ( g, |
| get( &SPPRC_Example_Graph_Vert_Prop::num, g ), |
| get( &SPPRC_Example_Graph_Arc_Prop::num, g ), |
| s, |
| t, |
| opt_solutions_spptw, |
| pareto_opt_rcs_spptw, |
| spp_spptw_res_cont( 0, 0 ), |
| ref_spptw(), |
| dominance_spptw(), |
| std::allocator |
| <r_c_shortest_paths_label |
| <SPPRC_Example_Graph, spp_spptw_res_cont> >(), |
| default_r_c_shortest_paths_visitor() ); |
| |
| std::cout << "SPP with time windows:" << std::endl; |
| std::cout << "Number of optimal solutions: "; |
| std::cout << static_cast<int>( opt_solutions.size() ) << std::endl; |
| for( int i = 0; i < static_cast<int>( opt_solutions.size() ); ++i ) |
| { |
| std::cout << "The " << i << "th shortest path from A to E is: "; |
| std::cout << std::endl; |
| for( int j = static_cast<int>( opt_solutions_spptw[i].size() ) - 1; |
| j >= 0; |
| --j ) |
| std::cout << name[source( opt_solutions_spptw[i][j], g )] << std::endl; |
| std::cout << "E" << std::endl; |
| std::cout << "Length: " << pareto_opt_rcs_spptw[i].cost << std::endl; |
| std::cout << "Time: " << pareto_opt_rcs_spptw[i].time << std::endl; |
| } |
| |
| // utility function check_r_c_path example |
| std::cout << std::endl; |
| bool b_is_a_path_at_all = false; |
| bool b_feasible = false; |
| bool b_correctly_extended = false; |
| spp_spptw_res_cont actual_final_resource_levels( 0, 0 ); |
| graph_traits<SPPRC_Example_Graph>::edge_descriptor ed_last_extended_arc; |
| check_r_c_path( g, |
| opt_solutions_spptw[0], |
| spp_spptw_res_cont( 0, 0 ), |
| true, |
| pareto_opt_rcs_spptw[0], |
| actual_final_resource_levels, |
| ref_spptw(), |
| b_is_a_path_at_all, |
| b_feasible, |
| b_correctly_extended, |
| ed_last_extended_arc ); |
| if( !b_is_a_path_at_all ) |
| std::cout << "Not a path." << std::endl; |
| if( !b_feasible ) |
| std::cout << "Not a feasible path." << std::endl; |
| if( !b_correctly_extended ) |
| std::cout << "Not correctly extended." << std::endl; |
| if( b_is_a_path_at_all && b_feasible && b_correctly_extended ) |
| { |
| std::cout << "Actual final resource levels:" << std::endl; |
| std::cout << "Length: " << actual_final_resource_levels.cost << std::endl; |
| std::cout << "Time: " << actual_final_resource_levels.time << std::endl; |
| std::cout << "OK." << std::endl; |
| } |
| |
| return 0; |
| } |