An ALGOL 68 Package for Implementing Graph Algorithms

The implementation of graph-theoretic algorithms using the facilities of standard algorithmic languages is not easy since data structures and operations natural to the subject are not readily available. GRAAP (GRaph Algorithmic Applications Package) is a new system designed to solve this problem. Written in ALGOL 68-R it consists of about 150 operators and procedures which perform operations natural to graph theory and essential to the implementation of graph algorithms. These operators and procedures manipulate information representing graphs and related objects stored in suitably defined structures. GRAAP exists as an album of precompiled segments to minimise compilation time. The operations provided and the transparent internal representations of graphs of different kinds are discussed. The ease with which algorithms can be implemented is demonstrated by examples.