A Recursive Approach to the Implementation of Enumerative Methods

Abstract

Algorithms for generating permutations by means of both lexicographic and minimum-change methods are presented. A recursive approach to their implementation leads to transparent procedures that are easily proved correct; moreover, they turn out to be no less efficient than previous iterative generators. Some applications of explicit enumeration to combinatorial optimization problems, exploiting the minimum-change property, are indicated. Finally, a recursive approach to implicit enumeration is discussed.