Near in Place Linear Time Minimum Redundancy Coding

Abstract

In this paper we discuss data structures and algorithms for linear time encoding and decoding of minimum redundancy codes. We show that a text of length n over an alphabet of cardinality σ can be encoded to minimum redundancy code and decoded from minimum redundancy code in time O(n) using only an additional space of O(σ) words (O(σ log n) bits) for handling the auxiliary data structures. The encoding process can replace the given block code by the corresponding minimum redundancy code in place. The decoding process is able to replace the minimum redundancy code given in sufficient space to store the block code by the corresponding block code.