hm_heuristic.h

#ifndef HEURISTICS_HM_HEURISTIC_H
#define HEURISTICS_HM_HEURISTIC_H
 
#include "downward/heuristic.h"
 
#include <algorithm>
#include <iostream>
#include <map>
#include <string>
#include <vector>
 
namespace hm_heuristic {
/*
  Haslum's h^m heuristic family ("critical path heuristics").
 
  This is a very slow implementation and should not be used for
  speed benchmarks.
*/
 
class HMHeuristic : public Heuristic {
    using Tuple = std::vector<FactPair>;
    // parameters
    const int m;
    const bool has_cond_effects;
 
    const Tuple goals;
 
    // h^m table
    std::map<Tuple, int> hm_table;
    bool was_updated;
 
    // auxiliary methods
    void init_hm_table(const Tuple& t);
    void update_hm_table();
    int eval(const Tuple& t) const;
    int update_hm_entry(const Tuple& t, int val);
    void extend_tuple(const Tuple& t, const OperatorProxy& op);
 
    int check_tuple_in_tuple(const Tuple& tuple, const Tuple& big_tuple) const;
 
    int get_operator_pre_value(const OperatorProxy& op, int var) const;
    Tuple get_operator_pre(const OperatorProxy& op) const;
    Tuple get_operator_eff(const OperatorProxy& op) const;
    bool contradict_effect_of(const OperatorProxy& op, int var, int val) const;
 
    void generate_all_tuples();
    void generate_all_tuples_aux(int var, int sz, const Tuple& base);
 
    void generate_all_partial_tuples(
        const Tuple& base_tuple,
        std::vector<Tuple>& res) const;
    void generate_all_partial_tuples_aux(
        const Tuple& base_tuple,
        const Tuple& t,
        int index,
        int sz,
        std::vector<Tuple>& res) const;
 
    void dump_table() const;
 
protected:
    virtual int compute_heuristic(const State& ancestor_state) override;
 
public:
    HMHeuristic(
        int m,
        const std::shared_ptr<AbstractTask>& transform,
        bool cache_estimates,
        const std::string& description,
        utils::Verbosity verbosity);
 
    virtual bool dead_ends_are_reliable() const override;
};
} // namespace hm_heuristic
 
#endif