Abstract: A compression coding method, apparatus, and program suitable for continuously coding pieces of fixed length data are provided. The compression coding method includes: dividing, into columns each with a predetermined bit width, records consisting of a fixed-length bit string that includes one or more fields, pieces of data of the same type being contained in the same field among fields determined in advance; and determining, for each column, a probability of occurrence of a bit value in the column at the same position among a plurality of records, and coding the plurality of records on the basis of the probability of occurrence using an entropy coding method.

Abstract: A code ID range table holding code ID ranges for each code of a same code type and a next code ID table holding next code IDs are created. Code ID ranges of code types of codes configuring a search code string are read out from the code ID range table for the search target code string, and the stored next code ID corresponding to a code ID included in the code ID range of the code type of the head code in the search code string is read out from the next code ID table while the stored next code IDs corresponding to the next codes are successively read out from the next code ID table, and the next code ID read out from the next code ID table is verified whether it is included in the code ID range read out from the code ID range table.

Abstract: A map difference data generation apparatus includes: most recent and supplementary map data storage devices storing primary most recent and supplementary map data, respectively; a map update reflection device generating secondly most recent and supplementary map data according to an update of a first link, and generating tertiary most recent and supplementary map data according to an update of a second link; a determination device determining a dependency relationship between the update of the first and second links, in accordance with results of searching a route in the tertiary most recent and supplementary map data between first and second nodes, which are both ends of the second link; and a map difference data generation device generating map difference data, which defines a combination of the update of the first and second links, when the update of the first and second links have the dependency relationship.

Abstract: In map data having link information, each of the links has reference information regarding a start point node of the link, a next link in a series of links, and an upper link. Further, links are memorized in a form of link list, and the position of the link in the link list is not changed in the course of adding/deleting a link, thereby enabling a direct reference to each of the links in the link list by the position of the link. The link information organized in the above-described manner enables the ease of the update of the map data as well as the speed-up of the calculation of, for example, a navigation route.

Abstract: The sort processing of keys to be sorted, which keys are expressed as bit strings involves a classification processing. In the classification processing, a bit string comparison between a reference key and a key which is an object of the classification is performed, and a difference bit position is obtained that is the bit position of the first bit that differs in the bit string comparison and the keys to be sorted are classified by the difference bit position into key groups with the same difference bit position.

Abstract: A coupled node tree has a root node and a node pair, the node pair being a branch node, which includes position information of a link target node pair, and a leaf node, which includes a search target index key, or a pair of branch nodes, or a pair of leaf nodes located in adjacent storage areas. The nodes of the coupled node tree are backed up in a depth precedence search sequence. The coupled node tree is restored by repeating the following process: reading out the nodes in the sequence they are backed up, storing in a stack the position information of the node to be restored, successively restoring child nodes as long as branch nodes are encountered, restoring a leaf node which is read out and then, tracing back up the stack, a decision being made as to which node is next to be restored.

Abstract: A map difference data generation apparatus includes: most recent and supplementary map data storage devices storing primary most recent and supplementary map data, respectively; a map update reflection device generating secondly most recent and supplementary map data according to an update of a first link, and generating tertiary most recent and supplementary map data according to an update of a second link; a determination device determining a dependency relationship between the update of the first and second links, in accordance with results of searching a route in the tertiary most recent and supplementary map data between first and second nodes, which are both ends of the second link; and a map difference data generation device generating map difference data, which defines a combination of the update of the first and second links, when the update of the first and second links have the dependency relationship.

Abstract: To realize a high speed merge sort method by applying a coupled node tree, which method extracts a smallest or largest key from a plurality of sorted key storage areas in each of which is stored keys including bit strings that are sorted, and generates a coupled node tree for merge while adding a processing source identifier that identifies the sorted storage area wherefrom the key has been extracted, and repeats the actions of writing out into the merged key storage area a key being obtained by a minimum or maximum value search on the coupled node tree and deleting the key, and inserting into the coupled node tree a key by extracting the key from one of the plurality of sorted key storage areas.

Abstract: To perform a path finding for a network by traversing mutually connected links by means of a link destination table that is a data configuration for representing the network. The link destination table contains, for link IDs of each of the links in the network, a node ID of a node on one side of the link, destination link IDs for the node on one side which are link IDs of other links to that node, a node ID of the node on the other side of the link, destination link IDs of the node on the other side which are link IDs of other links to that node, and interval costs.

Abstract: In map data having link information, each of the links has reference information regarding a start point node of the link, a next link in a series of links, and an upper link. Further, links are memorized in a form of link list, and the position of the link in the link list is not changed in the course of adding/deleting a link, thereby enabling a direct reference to each of the links in the link list by the position of the link. The link information organized in the above-described manner enables the ease of the update of the map data as well as the speed-up of the calculation of, for example, a navigation route.