aoc2024/day21/segmented_sequences.h

#ifndef SEGMENTED_SEQUENCES_H
#define SEGMENTED_SEQUENCES_H

#include <string>
#include <memory>
#include <vector>
#include <variant>
#include <optional>
#include <functional>

using SegmentedString = std::vector<std::shared_ptr<std::string>>;

class SegmentedSequences {
public:
  SegmentedSequences() = default;
  virtual ~SegmentedSequences() = default;

  virtual void Visit(std::function<void(SegmentedString sequence)> visitor) const = 0;
  virtual size_t MinSize() const = 0;
};

class SegmentedSequencesLeaf : public SegmentedSequences {
private:
  std::shared_ptr<std::string> sequence_;
public:
  SegmentedSequencesLeaf() = default;
  ~SegmentedSequencesLeaf() override = default;
  explicit SegmentedSequencesLeaf(std::shared_ptr<std::string> sequence);

  void Visit(std::function<void(SegmentedString sequence)> visitor) const override;
  size_t MinSize() const override;

  const std::string& sequence() const { return *sequence_; }
};

class SegmentedSequencesAlternatives : public SegmentedSequences {
private:
  std::vector<std::shared_ptr<SegmentedSequences>> alternatives_;
  size_t min_size_ = 0;

public:
  SegmentedSequencesAlternatives() = default;
  ~SegmentedSequencesAlternatives() override = default;
  explicit SegmentedSequencesAlternatives(
      std::vector<std::shared_ptr<SegmentedSequences>> alternatives);

  void Visit(std::function<void(SegmentedString sequence)> visitor) const override;
  size_t MinSize() const override;

  const std::vector<std::shared_ptr<SegmentedSequences>>& alternatives() const {
    return alternatives_;
  }
};

class SegmentedSequencesProduct : public SegmentedSequences {
private:
  std::shared_ptr<SegmentedSequences> a_;
  std::shared_ptr<SegmentedSequences> b_;
  size_t min_size_ = 0;

public:
  SegmentedSequencesProduct() = default;
  ~SegmentedSequencesProduct() override = default;
  SegmentedSequencesProduct(std::shared_ptr<SegmentedSequences> a,
                            std::shared_ptr<SegmentedSequences> b);

  void Visit(std::function<void(SegmentedString sequence)> visitor) const override;
  size_t MinSize() const override;

  std::shared_ptr<SegmentedSequences> a() const { return a_; }
  std::shared_ptr<SegmentedSequences> b() const { return b_; }
};

#endif