The document discusses different data structures used to organize and store data in a computer including arrays, stacks, queues, linked lists, trees, and graphs. It provides examples of each data structure and how they are used, such as stacks being used for undo functions in text editors and queues being used for processes in operating systems and packets in data communication. Trees and graphs are described as tools for organizing hierarchical relationships and mapping relationships between data objects.

2. It is a particular way of organizing and
storing data in a computer so, that it can be
accessed and modified efficiently

3.  Array
 Stack
 Queue
 Link list
 Tree
 Graph

4.  It is a collection of elements each identified
by at least one array index or key
 An array is stored so that the position of
each element can be computed from its
index

6.  It is a container of objects that are inserted
and removed according to the last-in first-
out (LIFO) principle.
 push
 pop

8. 

9.  To reverse a word. You push a given word
to stack - letter by letter - and then pop
letters from the stack.
 An "undo" mechanism in text editors; this
operation is accomplished by keeping all text
changes in a stack.

10. A B C D
cD A
Letters Removed from the stack
Letter inserted into the stack
B

11.  The first element is inserted from one end
called REAR.
 The Deletion of existing element takes place
from the other end called as FRONT.

12.  This makes queue as FIFO(First in First
Out) data structure, which means that
element inserted first will also be removed
first.

14. 

15. 

16.  Queue of processes in OS.
 Queue of packets in data communication.

17. 

18. 

19.  A linked list is a dynamic data structure.
 The number of nodes in a list is not fixed
and can grow and shrink on demand.

20.  A singly linked list
 A doubly linked list

21.  Each element of a list is comprising of two items
 The data and a reference to the next node.

23.  Treasure hunt

25.  A doubly linked list is a list that has two
references, one to the next node and
another to previous node.

27.  A music player which has next and prev
buttons. –
 Train, here each coach is connected to its
previous and next coach

29.  It is a powerful tool for organizing data
objects based on keys.
 It is equally useful for organizing multiple
data objects in terms of hierarchical
relationships

31.  Unix and DOS operating system

32. 

33.  The map will store (word, definition of word)
pairs.
• key = word
• note: words are unique
• value = definition of word
• get(word)
• returns the definition if the word is in
dictionary
• returns null if the word is not in dictionary

34.  LANGUAGE DICTIONARY.

35. 

36.  Google MAPS

38. 