10. Data Structures GapFill

A data structure is a means by which data is stored in an organised way.  While variables are sometimes described as data structures, the term tends to apply to a single structure that can store multiple data items.  A(n)  queuearrayliststack is one such data structure, in which a fixed number of spaces, called  boxespigeonholesreferenceselements, are created  when the application begins executionwhen the data structure is initialisedwhen the containing subroutine is calledwhen the data structure is declared.  Each one of these spaces is addressable via a(n)  indexreferencepointerstub, the first being  n-1n01 and the last being  n-1n+1n-1.

An alternative to this data structure is a  linkedserialconnectedsequential list, which is made up of a series of  nodespointersspaceselements, each comprising two components.  The data itself is one of these, and the other is a  hashvariabledisk addresspointer to the next item in the list.  A(n)  stacklistarrayqueue is an example of a last-in-first-out data structure, in which only the most recently added data item is accessible.  Data items can be  pulledpoppedpeekedpushed onto the structure or  placedpoppedpulledpushed from it, the latter of which entails removing it.  A related data structure is a(n)  liststackqueuearray, which is an example of a first-in-first-out data structure.

A(n)  arrayqueuetreestack is a specific type of  graphstackarrayqueue, in which each item of data points to other pieces of data.  This is a non-linear, hierarchical data structure, with the  rootbranchbaseleaf conceptually at the top.