Session 1-Pointer, Array and Introduction to Data Structure-2101727190-Fedrick

Hi everybody, today i will explain 4 topic about data structure, first of all i will explain about:

Array
Array is a collection of data of same types stored in sequential memory location. It is a linear data structure, where data is stored sequentially one after the other. The elements in an array is accessed using an index. For example, In an array of n elements, the first element has index zeroand the last element has index (n-1). Elements with consecutive index (i.e. i and i+1) are stored in consecutive memory location in the system.

Array can be divided into following types:

1. One Dimensional Array

example:

• int var [10]; (declaration)

• var [2] = 12; (adding value)

so, the value on row -> 3 = 12

(why row 3? because array always start from 0)

2. Multi Dimensional Array

example 2 dimensional array:

• int var [10] [10]; (declares an integer array with 10 elements)

• var [2] [4] = 14; (accessing an integer array with 14 value)

so, the value on coloum -> 3 and row -> 5 = 14

array have more than 2 dimension, and all of them working like the examples on the top.

There are a number of operations that can be performed on arrays.

They are:

• Traversal

• Insertion

• Searching

• Deletion

• Merging

• Sorting

Pointer

C++ pointers are easy and fun to learn. Some C++ tasks are performed more easily with pointers, and other C++ tasks, such as dynamic memory allocation, cannot be performed without them.

As you know every variable is a memory location and every memory location has its address defined which can be accessed using ampersand (&) operator which denotes an address in memory. Consider the following which will print the address of the variables defined −

The two most important operators used with pointer type are:

• &  (the address operator)

• *   (the dereferencing operator)

example:

If we have the declaration:

  int test;

  int *ptest;

then test is an integer and ptest is a pointer to an integer. If we say:

  ptest  = &test;

then &test returns the address of x and assigns it as the value of ptest.

To assign a value of x we can say

  x = 10;

or

  *ptest = 10;

Data Structure

Data structures are used to store data in a computer in an organized form. In C language Different types of data structures are; Array, Stack, Queue, Linked List, Binary Tree, Hash Tables.

• Array: Array is collection of similar data type, you can insert and deleted element form array without follow any order.
• Stack: Stack work on the basis of Last-In-First-Out (LIFO). Last entered element removed first.

• Queue: Queue work on the basis of First-In-First-Out (FIFO). First entered element removed first.

• Linked List: Linked list is the collection of node, Here you can insert and delete data in any order.

• Binary Tree: Stores data in a non linear form with one root node and sub nodes.

• Hash Tables: Stores data in tables form.

Data Type
A data type defines what kind of value a column can hold: integer data, character data, monetary data, date and time data, binary strings, and so on.

example of predefined data types are:
• Int : (4), (6), (9)
• Char : (A), (D), (C)
• Float : (1,35), (3,567546)

•Abstract Data Type (ADT)

is a data type that is organized in such a way that the specification of the objects and the

specification of the operations on the objects is separated from the representation of the 

objects and the implementation of the operations.

Question

1. How many dimension in array (max).

2. What is the different between single pointer and double pointer.

3. How many pointer we can use (max).

Answer

1. maximum dimension we can use in array are 256 dimension.

2. Printed addresses become slightly different, when new line starts. If I use static array,

addresses are exactly the same, and array elements are going one after another.

Presumably, you're talking about a static array of arrays and compare it to the array of

pointers that you have.

Elements of an array are allocated continuously in memory. In the case of array of static

arrays, the elements of the outer array are static arrays and they are stored continuously in

memory. In the case of array of pointers, the elements of the outer array are the pointers

and they are also stored continuously in memory. The arrays of int that you allocate

dynamically on the other hand are not stored in the outer array. Where they're stored is

implementation defined and typically not related to the location of the array which holds the

pointers.

Extension.

Why we need to use Double Pointer?

If you want to have a list of characters (a word), you can use char *word

If you want a list of words (a sentence), you can use char **sentence

If you want a list of sentences (a monologue), you can use char ***monologue

If you want a list of monologues (a biography), you can use char ****biography

If you want a list of biographies (a bio-library), you can use char *****biolibrary

       etc.

3.Its depend by your computer, how far your computer can process it.

Thats all thank you :)