Path searching method and path search device

A path search device comprising:

• a memory;
• and
• a processor that:
• searches for one node by a first search method from a plurality of nodes to be searched which have not yet been searched for and are adjacent to a node that is recorded as an already-searched-for node among a plurality of nodes, in a path search from a first node to a second node out of the plurality of nodes where information expressed by the plurality of nodes and a plurality of links each of which connects two nodes from the plurality of nodes and to each of which a cost is set is used;
• records in the memory a distance between the node searched for in searching and the second node, and records the node searched for in the memory as the already-searched-for node;
• changes the first search method to a second search method in which a number of nodes to be searched is prevented from increasing according to distances between the second node and two or more nodes recorded as the already-searched-for node obtained as a result of performing searching and recording two or more times;
• and generates path information according to a node searched for by the second search method.

A non-transitory computer-readable recording medium having stored therein a program for causing a computer to execute a process comprising:

• searching for one node by a first search method from a plurality of nodes to be searched which have not yet been searched for and are adjacent to a node that is recorded as an already-searched-for node among a plurality of nodes, in a path search from a first node to a second node out of the plurality of nodes where information expressed by the plurality of nodes and a plurality of links each of which connects two nodes from the plurality of nodes and to each of which a cost is set is used;
• recording a distance between the node searched for in the searching and the second node, and recording the node searched for as the already-searched-for node;
• changing the first search method to a second search method in which a number of nodes to be searched is prevented from increasing according to distances between the second node and two or more nodes recorded as the already-searched-for nodes obtained as a result of performing the searching and the recording two or more times;
• and
• generating path information according to a node searched for by the second search method.