An efficient digital search algorithm by using a double-array structure

An efficient digital search algorithm is presented by introducing a new data structure, called a double-array, which combines the fast access of a matrix form with the compactness of a list form. Each transition of the search tree can be computed from the double-array in O(1) time; in other words, the worst-case time for retrieving a key becomes O(k) for the length k of that key. It is theoretically verified that each worst-case time of insertion and deletion is O(m) and O(m*e+e/sup 2/), respectively, where m is the number of redundant-state numbers in the double-array and e is the density of the transition labels. Simulation results are discussed.<>