Algorithms

A bag is a collection where removing items is not supported—its purpose is to provide clients with the ability to collect items and then to iterate through the collected items (the client can also test if a bag is empty and find its number of items). The order of iteration is unspecified and should be immaterial to the client. To appreciate the concept, consider the idea of an avid marble collector, who might put marbles in a bag, one at a time, and periodically process all the marbles to look for one having some particular characteristic

API
The symbol table is a prototypical abstract data type (see CHAPTER 1): it represents a well-defined set of values and operations on those values, enabling us to develop clients and implementations separately. As usual, we precisely define the operations by specifying an applications programming interface (API) that provides the contract between client and implementation:

Shortest ancestral path 598