The Theory and Practice of Constructing an Optimal Polyphase Sort
M. C. Er, Barry G. T. Lowden · The Computer Journal · 1982
The construction of both an optimal read-forward polyphase sort and a near optimal read-backward version is described. The former minimizes the merge volume, for a given distribution of strings, without the use of auxiliary data structures, and incorporates a new technique for computing the positions of dummy strings. In the case of the read-backward version, an approach is developed which achieves a merge volume nearest to the minimum, inasmuch as the theoretical optimal read-backward polyphase sort cannot be realized. A dispersion algorithm is also described which optimizes the distribution of strings so that minimum merge volume is assured.