AllDiff.h

/*
 * AllDiff.h
 * @brief General "all-different" constraint
 * @date Feb 6, 2012
 * @author Frank Dellaert
 */
 
#pragma once
 
#include <gtsam/discrete/DiscreteKey.h>
#include <gtsam_unstable/discrete/BinaryAllDiff.h>
 
namespace gtsam {
 
class GTSAM_UNSTABLE_EXPORT AllDiff : public Constraint {
  std::map<Key, size_t> cardinalities_;
 
  DiscreteKey discreteKey(size_t i) const {
    Key j = keys_[i];
    return DiscreteKey(j, cardinalities_.at(j));
  }
 
 public:
  AllDiff(const DiscreteKeys& dkeys);
 
  // print
  void print(const std::string& s = "", const KeyFormatter& formatter =
                                            DefaultKeyFormatter) const override;
 
  bool equals(const DiscreteFactor& other, double tol) const override {
    if (!dynamic_cast<const AllDiff*>(&other))
      return false;
    else {
      const AllDiff& f(static_cast<const AllDiff&>(other));
      return cardinalities_.size() == f.cardinalities_.size() &&
             std::equal(cardinalities_.begin(), cardinalities_.end(),
                        f.cardinalities_.begin());
    }
  }
 
  double operator()(const Values& values) const override;
 
  DecisionTreeFactor toDecisionTreeFactor() const override;
 
  DecisionTreeFactor operator*(const DecisionTreeFactor& f) const override;
 
  /*
   * Ensure Arc-consistency
   * Arc-consistency involves creating binaryAllDiff constraints
   * In which case the combinatorial hyper-arc explosion disappears.
   * @param j domain to be checked
   * @param domains all other domains
   */
  bool ensureArcConsistency(size_t j,
                            std::vector<Domain>& domains) const override;
 
  Constraint::shared_ptr partiallyApply(const Values&) const override;
 
  Constraint::shared_ptr partiallyApply(
      const std::vector<Domain>&) const override;
};
 
}  // namespace gtsam