distances.h

#ifndef DISTANCES_H
#define DISTANCES_H
 
#include <unordered_map>
#include <vector>
#include <memory>
#include <cstdint>
 
namespace mazes {
 
class grid;
 
class distances {
public:
    explicit distances(int32_t root_index);
 
    int& operator[](int32_t index) noexcept;
 
    const int& operator[](int32_t index) const noexcept;
 
    void set(int32_t index, int distance) noexcept;
 
    bool contains(int32_t index) const noexcept;
 
    std::shared_ptr<distances> path_to(int32_t goal_index, const grid& grid) const noexcept;
 
    std::pair<int32_t, int> max() const noexcept;
 
    void collect_keys(std::vector<int32_t>& indices) const noexcept;
 
private:
    int32_t m_root_index;
    std::unordered_map<int32_t, int> m_cells;
}; // class distances
 
} // namespace mazes
 
#endif // DISTANCES_H