4#include <unordered_map>
23 using GridCell = std::list<T>;
33 void insert(
int x,
int y,
int z, T item);
42 void remove(
int x,
int y,
int z, T item);
53 std::optional<GridCell>
getCell(
int x,
int y,
int z);
55 std::unordered_map<std::tuple<int,int,int>, GridCell> cellMap;