Bidirectional data structure processing

To enhance data structure processing performance, data is organized bi-directionally in a data structure. That is, depending on the value of a data key associated with an entry, the entry is stored either from a low end or from a high end of the data structure. For example, the low end of the data structure may store entries having even-valued keys, while the high end of the data structure may store entries having odd-valued keys. Subsequent data structure processing can be facilitated by searching the data structure in either a forward direction starting with the low end or a reverse direction starting with the high end, depending on whether a search key is even or odd.