An efficient compression method for Patricia tries

In many applications, information retrieval is a very important research field. In several key strategies, the trie is famous as a fast access method to be able to retrieve keys in order. Especially, the Patricia trie gives the shallowest trie by eliminating all single descendant nodes, for this reason, the Patricia trie is often used as indices of information retrieval systems. If trie structures are implemented, however, the greater the number of registered keys, the larger storage is required. Jonge et al. (1987) proposed a method to change the normal binary trie into a compact bit stream. This paper shows the method for compressing the Patricia trie into the new bit stream. The theoretical and experimental results show that this method generates 40/spl sim/60 percent shorter than the traditional method. This method thus enables us to provide more compact storage and faster access than the traditional method.