Patent ID: 7403495

Claim:
A method for compressing a tree, the tree including a plurality of nodes, each node associated with a node identifier and a parent node identifier, the method comprising: a. setting a current node identifier as a root node of the tree; b. if the current node identifier references a node to be deleted: deleting the node referenced by the current node identifier from the tree; storing the current node identifier; storing a parameter representing a number of nodes currently having been deleted from the tree, such that the parameter is associated with the stored current node identifier; and updating the current node identifier to reference a next node of the tree; c. if an identifier for a parent node of the node referenced by the current node identifier has previously been stored: setting the node identifier of the current node as a difference of the node identifier referenced by the current node identifier and a total number of nodes having been currently deleted from the tree; and setting the parent identifier of the current node as a difference of a node identifier of the parent node and the parameter associated with the parent identifier; and d. setting the current node to an unvisited child node of the current node.