This book was motivated by my experience in teaching the course E&CE 250: Algorithms and Data Structures in the Computer Engineering program at the University of Waterloo. I have observed that the advent of object-oriented methods and the emergence of object-oriented design patterns has lead to a profound change in the pedagogy of data structures and algorithms. The successful application of these techniques gives rise to a kind of cognitive unification: Ideas that are disparate and apparently unrelated seem to come together when the appropriate design patterns and abstractions are used.
This paradigm shift is both evolutionary and revolutionary. On the one hand, the knowledge base grows incrementally as programmers and researchers invent new algorithms and data structures. On the other hand, the proper use of object-oriented techniques requires a fundamental change in the way the programs are designed and implemented. Programmers who are well schooled in the procedural ways often find the leap to objects to be a difficult one.