Data types

 Linear Data Structures: A data structure is called linear if all of its elements are arranged in the

linear order. In linear data structures, the elements are stored in non-hierarchical way where each element

has the successors and predecessors except the first and last element.

Types of Linear Data Structures are given below:

Arrays: An array is a collection of similar type of data items and each data item is called an element of

the array. The data type of the element may be any valid data type like char, int, float or double.

The elements of array share the same variable name but each one carries a different index number known

as subscript. The array can be one dimensional, two dimensional or multidimensional.

The individual elements of the array age are:

age[0], age[1], age[2], age[3],......... age[98], age[99].

Linked List: Linked list is a linear data structure which is used to maintain a list in the memory. It can be

seen as the collection of nodes stored at non-contiguous memory locations. Each node of the list contains

a pointer to its adjacent node.

Stack: Stack is a linear list in which insertion and deletions are allowed only at one end, called top.

A stack is an abstract data type (ADT), can be implemented in most of the programming languages. It is

named as stack because it behaves like a real-world stack, for example: - piles of plates or deck of cards

etc.

Queue: Queue is a linear list in which elements can be inserted only at one end called rear and deleted

only at the other end called front.

It is an abstract data structure, similar to stack. Queue is opened at both end therefore it follows First-In-

First-Out (FIFO) methodology for storing the data items.

Non Linear Data Structures:

This data structure does not form a sequence i.e. each item or element is connected with two or more

other items in a non-linear arrangement. The data elements are not arranged in sequential structure.

Types of Non Linear Data Structures are given below:

Trees: Trees are multilevel data structures with a hierarchical relationship among its elements known as

nodes. The bottommost nodes in the hierarchy are called leaf node while the topmost node is called root

node. Each node contains pointers to point adjacent nodes.

Tree data structure is based on the parent-child relationship among the nodes. Each node in the tree can

have more than one children except the leaf nodes whereas each node can have atmost one parent except the root node. Trees can be classified into many categories which will be discussed later in this tutorial.

Graphs: Graphs can be defined as the pictorial representation of the set of elements (represented by

vertices) connected by the links known as edges. A graph is different from tree in the sense that a graph

can have cycle while the tree cannot have the one.