/* Copyright (c) 2017 Microsoft Corporation Author: Nikolaj Bjorner, Lev Nachmanson */ #pragma once #include "util/vector.h" #include #include "util/debug.h" #include "util/buffer.h" #include #include #include #include "util/lp/lar_constraints.h" #include #include "util/lp/lar_core_solver.h" #include #include "util/lp/numeric_pair.h" #include "util/lp/scaler.h" #include "util/lp/lp_primal_core_solver.h" #include "util/lp/random_updater.h" #include #include "util/lp/stacked_map.h" #include "util/lp/stacked_value.h" #include "util/lp/stacked_vector.h" #include "util/lp/stacked_unordered_set.h" #include "util/lp/iterator_on_pivot_row.h" #include "util/lp/implied_bound.h" #include "util/lp/bound_analyzer_on_row.h" #include "util/lp/iterator_on_term_with_basis_var.h" #include "util/lp/iterator_on_row.h" #include "util/lp/quick_xplain.h" #include "util/lp/conversion_helper.h" #include "util/lp/int_solver.h" #include "util/lp/nra_solver.h" namespace lp { class lar_solver : public column_namer { class ext_var_info { unsigned m_ext_j; // the external index bool m_is_integer; public: ext_var_info(unsigned j): ext_var_info(j, false) {} ext_var_info(unsigned j , bool is_int) : m_ext_j(j), m_is_integer(is_int) {} unsigned ext_j() const { return m_ext_j;} bool is_integer() const {return m_is_integer;} }; //////////////////// fields ////////////////////////// lp_settings m_settings; stacked_value m_status; stacked_value m_simplex_strategy; std::unordered_map m_ext_vars_to_columns; vector m_columns_to_ext_vars_or_term_indices; stacked_vector m_vars_to_ul_pairs; vector m_constraints; stacked_value m_constraint_count; // the set of column indices j such that bounds have changed for j int_set m_columns_with_changed_bound; int_set m_rows_with_changed_bounds; int_set m_basic_columns_with_changed_cost; stacked_value m_infeasible_column_index; // such can be found at the initialization step stacked_value m_term_count; vector m_terms; const var_index m_terms_start_index; indexed_vector m_column_buffer; public: lar_core_solver m_mpq_lar_core_solver; unsigned constraint_count() const; const lar_base_constraint& get_constraint(unsigned ci) const; ////////////////// methods //////////////////////////////// static_matrix> & A_r(); static_matrix> const & A_r() const; static_matrix & A_d(); static_matrix const & A_d() const; static bool valid_index(unsigned j){ return static_cast(j) >= 0;} bool column_is_int(unsigned j) const; bool column_is_fixed(unsigned j) const; public: // init region bool strategy_is_undecided() const; var_index add_var(unsigned ext_j, bool is_integer); void register_new_ext_var_index(unsigned ext_v, bool is_int); bool term_is_int(const lar_term * t) const; bool var_is_int(var_index v) const; bool ext_var_is_int(var_index ext_var) const; void add_non_basic_var_to_core_fields(unsigned ext_j, bool is_int); void add_new_var_to_core_fields_for_doubles(bool register_in_basis); void add_new_var_to_core_fields_for_mpq(bool register_in_basis); var_index add_term_undecided(const vector> & coeffs, const mpq &m_v); // terms var_index add_term(const vector> & coeffs, const mpq &m_v); void add_row_for_term(const lar_term * term, unsigned term_ext_index); void add_row_from_term_no_constraint(const lar_term * term, unsigned term_ext_index); void add_basic_var_to_core_fields(); constraint_index add_var_bound(var_index j, lconstraint_kind kind, const mpq & right_side) ; void update_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index constr_index); void add_var_bound_on_constraint_for_term(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci); void add_constraint_from_term_and_create_new_column_row(unsigned term_j, const lar_term* term, lconstraint_kind kind, const mpq & right_side); void decide_on_strategy_and_adjust_initial_state(); void adjust_initial_state(); void adjust_initial_state_for_lu(); void adjust_initial_state_for_tableau_rows(); // this fills the last row of A_d and sets the basis column: -1 in the last column of the row void fill_last_row_of_A_d(static_matrix & A, const lar_term* ls); void update_free_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index constr_ind); void update_upper_bound_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci); void update_boxed_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci); void update_low_bound_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci); void update_fixed_column_type_and_bound(var_index j, lconstraint_kind kind, const mpq & right_side, constraint_index ci); //end of init region lp_settings & settings(); lp_settings const & settings() const; void clear(); lar_solver(); void set_propagate_bounds_on_pivoted_rows_mode(bool v); virtual ~lar_solver(); numeric_pair const& get_value(var_index vi) const; bool is_term(var_index j) const; unsigned adjust_term_index(unsigned j) const; bool use_lu() const; bool sizes_are_correct() const; void print_implied_bound(const implied_bound& be, std::ostream & out) const; bool implied_bound_is_correctly_explained(implied_bound const & be, const vector> & explanation) const; void analyze_new_bounds_on_row( unsigned row_index, bound_propagator & bp); void analyze_new_bounds_on_row_tableau( unsigned row_index, bound_propagator & bp ); void substitute_basis_var_in_terms_for_row(unsigned i); void calculate_implied_bounds_for_row(unsigned i, bound_propagator & bp); linear_combination_iterator * create_new_iter_from_term(unsigned term_index) const; unsigned adjust_column_index_to_term_index(unsigned j) const; void propagate_bounds_on_a_term(const lar_term& t, bound_propagator & bp, unsigned term_offset); void explain_implied_bound(implied_bound & ib, bound_propagator & bp); bool term_is_used_as_row(unsigned term) const; void propagate_bounds_on_terms(bound_propagator & bp); // goes over touched rows and tries to induce bounds void propagate_bounds_for_touched_rows(bound_propagator & bp); lp_status get_status() const; void set_status(lp_status s); lp_status find_feasible_solution(); lp_status solve(); void fill_explanation_from_infeasible_column(explanation_t & evidence) const; unsigned get_total_iterations() const; // see http://research.microsoft.com/projects/z3/smt07.pdf // This method searches for a feasible solution with as many different values of variables, reverenced in vars, as it can find // Attention, after a call to this method the non-basic variables don't necesserarly stick to their bounds anymore vector get_list_of_all_var_indices() const; void push(); static void clean_large_elements_after_pop(unsigned n, int_set& set); static void shrink_inf_set_after_pop(unsigned n, int_set & set); void pop(unsigned k); vector get_all_constraint_indices() const; bool maximize_term_on_tableau(const vector> & term, impq &term_max); bool costs_are_zeros_for_r_solver() const; bool reduced_costs_are_zeroes_for_r_solver() const; void set_costs_to_zero(const vector> & term); void prepare_costs_for_r_solver(const vector> & term); bool maximize_term_on_corrected_r_solver(const vector> & term, impq &term_max); // starting from a given feasible state look for the maximum of the term // return true if found and false if unbounded bool maximize_term(const vector> & term, impq &term_max); const lar_term & get_term(unsigned j) const; void pop_core_solver_params(); void pop_core_solver_params(unsigned k); void set_upper_bound_witness(var_index j, constraint_index ci); void set_low_bound_witness(var_index j, constraint_index ci); void substitute_terms_in_linear_expression( const vector>& left_side_with_terms, vector> &left_side, mpq & right_side) const; void detect_rows_of_bound_change_column_for_nbasic_column(unsigned j); void detect_rows_of_bound_change_column_for_nbasic_column_tableau(unsigned j); bool use_tableau() const; bool use_tableau_costs() const; void detect_rows_of_column_with_bound_change(unsigned j); void adjust_x_of_column(unsigned j); bool row_is_correct(unsigned i) const; bool ax_is_correct() const; bool tableau_with_costs() const; bool costs_are_used() const; void change_basic_x_by_delta_on_column(unsigned j, const numeric_pair & delta); void update_x_and_inf_costs_for_column_with_changed_bounds(unsigned j); void detect_rows_with_changed_bounds_for_column(unsigned j); void detect_rows_with_changed_bounds(); void update_x_and_inf_costs_for_columns_with_changed_bounds(); void update_x_and_inf_costs_for_columns_with_changed_bounds_tableau(); void solve_with_core_solver(); numeric_pair get_basic_var_value_from_row_directly(unsigned i); numeric_pair get_basic_var_value_from_row(unsigned i); template void add_last_rows_to_lu(lp_primal_core_solver & s); bool x_is_correct() const; bool var_is_registered(var_index vj) const; unsigned constraint_stack_size() const; void fill_last_row_of_A_r(static_matrix> & A, const lar_term * ls); template void create_matrix_A(static_matrix & matr); template void copy_from_mpq_matrix(static_matrix & matr); bool try_to_set_fixed(column_info & ci); column_type get_column_type(const column_info & ci); std::string get_column_name(unsigned j) const; bool all_constrained_variables_are_registered(const vector>& left_side); constraint_index add_constraint(const vector>& left_side_with_terms, lconstraint_kind kind_par, const mpq& right_side_parm); bool all_constraints_hold() const; bool constraint_holds(const lar_base_constraint & constr, std::unordered_map & var_map) const; bool the_relations_are_of_same_type(const vector> & evidence, lconstraint_kind & the_kind_of_sum) const; static void register_in_map(std::unordered_map & coeffs, const lar_base_constraint & cn, const mpq & a); static void register_one_coeff_in_map(std::unordered_map & coeffs, const mpq & a, unsigned j); bool the_left_sides_sum_to_zero(const vector> & evidence) const; bool the_right_sides_do_not_sum_to_zero(const vector> & evidence); bool explanation_is_correct(const vector>& explanation) const; bool inf_explanation_is_correct() const; mpq sum_of_right_sides_of_explanation(const vector> & explanation) const; bool has_lower_bound(var_index var, constraint_index& ci, mpq& value, bool& is_strict); bool has_upper_bound(var_index var, constraint_index& ci, mpq& value, bool& is_strict); void get_infeasibility_explanation(vector> & explanation) const; void get_infeasibility_explanation_for_inf_sign( vector> & explanation, const vector> & inf_row, int inf_sign) const; void get_model(std::unordered_map & variable_values) const; void get_model_do_not_care_about_diff_vars(std::unordered_map & variable_values) const; std::string get_variable_name(var_index vi) const; // ********** print region start void print_constraint(constraint_index ci, std::ostream & out) const; void print_constraints(std::ostream& out) const ; void print_terms(std::ostream& out) const ; void print_left_side_of_constraint(const lar_base_constraint * c, std::ostream & out) const; void print_term(lar_term const& term, std::ostream & out) const; mpq get_left_side_val(const lar_base_constraint & cns, const std::unordered_map & var_map) const; void print_constraint(const lar_base_constraint * c, std::ostream & out) const; void fill_var_set_for_random_update(unsigned sz, var_index const * vars, vector& column_list); void random_update(unsigned sz, var_index const * vars); void pivot_fixed_vars_from_basis(); void pop(); bool column_represents_row_in_tableau(unsigned j); void make_sure_that_the_bottom_right_elem_not_zero_in_tableau(unsigned i, unsigned j); void remove_last_row_and_column_from_tableau(unsigned j); void remove_last_column_from_tableau(unsigned j); void remove_last_column_from_basis_tableau(unsigned j); void remove_column_from_tableau(unsigned j); void pop_tableau(); void clean_inf_set_of_r_solver_after_pop(); void shrink_explanation_to_minimum(vector> & explanation) const; bool column_value_is_integer(unsigned j) const { const impq & v = m_mpq_lar_core_solver.m_r_x[j]; return v.is_int(); } bool column_is_real(unsigned j) const { return !column_is_int(j); } bool model_is_int_feasible() const; const impq & column_low_bound(unsigned j) const { return m_mpq_lar_core_solver.low_bound(j); } const impq & column_upper_bound(unsigned j) const { return m_mpq_lar_core_solver.upper_bound(j); } bool column_is_bounded(unsigned j) const { return m_mpq_lar_core_solver.column_is_bounded(j); } void get_bound_constraint_witnesses_for_column(unsigned j, constraint_index & lc, constraint_index & uc) const { const ul_pair & ul = m_vars_to_ul_pairs[j]; lc = ul.low_bound_witness(); uc = ul.upper_bound_witness(); } indexed_vector & get_column_in_lu_mode(unsigned j) { m_column_buffer.clear(); m_column_buffer.resize(A_r().row_count()); m_mpq_lar_core_solver.m_r_solver.solve_Bd(j, m_column_buffer); return m_column_buffer; } bool bound_is_integer_if_needed(unsigned j, const mpq & right_side) const; }; }