Types of datastructures

Types of datastructures

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  TYPES OF DATA STRUCTURES P.Prathibha, Lecturer
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  Topics Introduction to Datastructures Types of Data structures
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  Data structure is •representation of the logical relationship existing between individual elements of data. • a specialized format for organizing and storing data in memory that considers not only the elements stored but also their relationship to each other. • about arranging and storing of data in such a way so that it can be accessed and used efficiently. • We define a data structure as a way of organizing data that specifies 1. a set of data elements, i,e,, a data object; and 2. a set of operations that are applied to this data object. • These two sets form a mathematical construct that may be implemented using a particular programming language. • The data structure is independent of their implementation. Introduction to Data Structures
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  The various typesof data structures are: 1. Primitive and non-primitive 2. Linear and non-linear 3. Static and dynamic 4. Persistent and ephemeral 5. Sequential and direct access TYPES OF DATA STRUCTURES
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  Primitive and Non-PrimitiveData Structure  Primitive Data Structures are the basic data structures that directly operate upon the machine instructions.  Primitive data structures define a set of primitive elements that do not involve any other elements as its sub-parts. For example, data structures defined for integers and characters.  These are generally primary or built-in data types in programming languages  They have different representations on different computers.  Integers, Floating point numbers, Character constants, String constants and Pointers c ome under this category.  Non-primitive data structures are more complicated data structures and are derived f rom primitive data structures.  They emphasize on grouping same or different data items with relationship between each data item.  Arrays, Lists and Files come under this category.  Arrays in C++ consist of a set of similar type of elements.  Class and Structure are other examples of non-primitive data structures, which consist of a set of elements that may be of different data types and functions to o perate on.
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   A datastructure is said to be linear if its elements form a sequence or a linear list. Example: Arrays, linked list, stack, queue.  In a linear data structure, every data element has a unique successor and predecessor.  There are two basic ways of representing linear structures in memory.  One way is to have the relationship between the elements by means of pointers (links), called linked lists.  The other way is using sequential organization, that is, arrays.  In linear data structure, single level is involved. Therefore, we can traverse all the elements in single run only.  Linear data structures are easy to implement because computer memory is arranged in a linear way. Linear and Non-Linear Data Structure
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   Non-linear datastructure are used to represent the data containing hierarchical or network relationship among the elements. Examples: Trees, Graphs, Heaps etc.  In non-linear data structures, every data element may have more than one predecessor as well as successor.  Elements do not form any particular linear sequence.  In a non-linear data structure, single level is not involved. So, we can’t traverse all the elements in single run only.  Non-linear data structures are not easy to implement in comparison to linear data structure.  It utilizes computer memory efficiently in comparison to a linear data structure. contd..
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   A datastructure is static if it is created before program execution begins (also called during compilation time).  Static Data Structure means set of data, but that does not mean that we cannot ch ange the assigned value of elements.  Here static means the size of data type is fixed.  Memory size allocated to 'data' is fixed.  The variables of static data structure have user-specified names.  An array is a static data structure  Dynamic data structure is used for dynamic memory management.  A data structure that is created at run-time is called dynamic data structure.  The variables of this type are not always referenced by a user-defined name. The se are accessed  indirectly using their addresses through pointers.  A linked list is a dynamic data structure when realized using dynamic memory management and pointers.  Non-linear data structures are generally implemented in the same way as linked lists. Hence, trees and graphs can be implemented as dynamic data structures. Static and Dynamic Data structure
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  A data structurethat supports operations on the most recent version as well as the pervious is known as persistent data structure.  A persistent data structure is partially persistent if any version can be acces sed but only the most recent one can be updated; it is fully persistent if any v ersion can be both accessed and updated. An ephemeral data structure is one that supports operations only on the mo st recent version. The distinction between ephemeral and persistent data structure is essential ly the distinction between functional (also called effect free) and conventio nal imperative (also called effect full) programming paradigms.  The functional data structures are persistent and the imperative data struct ures are ephemeral.
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   Sequential accessmeans that to acces the nth element, we must access the preceeding (n-1) data elements.  A linked list is a sequential access data structure.  Direct access means that any element can be assessed without accessing its predecessor or successor, we can directly access the nth element.  An array is an example of direct access data structure.
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   Introduction toData structures  Types of Data structures Summary