Programmers Dojo

Arrays are one of the earliest data structures.  They are essentially just a block of memory which is accessed by offset.  Despite their simplicity there are still several broad categories each with their own sets of algorithms. Is the array a fixed size or can it grow as you add elements to it? A fixed size array is called a static array and one that can grow is called a dynamic array. Are the element all of the same type or can they be different? If they must all be the same type then the array are called homogeneous.  Otherwise it is a heterogeneous array. Finally, how many dimensions (subscripts) does the array have? For example, a 2 dimensioned array is a matrix. The number of dimensions doesn't change the structure of the array but changes the way elements are accessed. 

For our purposes I will propose 5 classes of data structures.  These being the array, list, tree, hash, and graph. Arrays Arrays are one of the most basic data structures and are characterized by direct access to every element in the structure.  It is easy to picture them as a line of numbered buckets where you can place an element into or remove an element from any bucket. Lists Lists are another very basic data structure.  In a list each node has one of more connections to other nodes.  Access to the list is only at one or both ends.  From any given element you can access any element which you have a connection to.  Here is an example of a simple list. Trees Trees are similar to lists in that each element has connections to other elements but in a tree the connections are more structured.  Each element in a tree can have children.  The number of children an element can have is an important property of a tree.  The top element in ...