| 摘要 |
<p>An apparatus receives coordinates of a location and selects an object of a first layer of a tree structure based on the coordinates. The apparatus determines whether data assigned to the selected object comprises an identifier of an area or a pointer to a set of objects of a respective next layer of the tree structure. If the data comprises a pointer to a set of objects, the apparatus selects one of the objects from the set of objects based on the received coordinates and continues with determining whether data assigned to the selected object comprises an identifier or a pointer. If the data comprises an identifier of an area, the apparatus reads the data comprising the identifier and provides the identifier as a result of a mapping of a location to an identifier of an area. A computer readable storage medium stores a database having a corresponding tree structure.</p> |
