A singly linked list is a linear data structure composed of nodes, where each node contains a data element and a link to the next node. The first node is referenced by a pointer called the head. Each node's link points to the next node in the list, with the last node's link pointing to null. Operations like insertion and deletion on singly linked lists can be performed by updating the links between nodes in constant time regardless of the list's size.

1. Singly Lists – Linked List
Representation

2. Outlines
 Singly link list
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3. Definition
Singly list :- is a linear data structure .it
is linearly connected .It contains node
s. Each node contains two parts, i.e. D
ATA part and LINK part.
 The data contains elements and
 Link contains address of another node.
3

4. link
data
A B C D
x
link
link link
Data
data
data
start
- START is List pointer contains address of the first node in
the List
- All nodes are connected to each other through Link fields
- Link of the last node is NULL pointer denoted by ‘X’ sign
- Null pointer indicated end of the list

5. Algorithms
 Lets consider,
• START is the 1st position in Linked List
• NewNode is the new node to be created
• DATA is the element to be inserted in new node
• POS is the position where the new node to be inserted
• TEMP and HOLD are temporary pointers to hold the nod
e address

6. Algorithm/c to Insert a Node at the beginning
 1. Input DATA to be inserted
 2. Create NewNode
 3. NewNode -> DATA = DATA
 4. If START is equal to NULL
 NewNode -> LINK = NULL
 5. Else
 NewNode -> LINK = START
 6. START = NewNode
 7. Exit

7. Insert a Node at the beginning
x
link
link link
data
data
data
start
NewNode

8. Algorithm/c to Insert a Node at the end
1. Input DATA to be inserted
2. Create NewNode
3. NewNode -> DATA = DATA
4. NewNode -> LINK = NULL
5. If START is equal to NULL
 a) START = NewNode
 6. Else
 a) TEMP = START
 b) while (TEMP -> LINK not equal to NU
LL)
 i) TEMP = TEMP -> LINK
 7. TEMP -> Link = NewNode
 8. Exit

9. Insert a Node at the end
link
data
A B C
link
link data
data
start
P
X
NewNode

10. Algorithm/c to Insert a Node at any specified position
1. Input DATA to be inserted and POS, the position to be in
serted.
2. Initialize TEMP = START and K=1
3. Repeat step 3 while ( K is less than POS)
 TEMP = TEMP -> LINK
 If TEMP -> LINK = NULL
 i) Exit
 K = K + 1
 4. Create a Newnode
 5. Newnode -> DATA = DATA
 6. Newnode -> LINK = TEMP -> LINK
 7. TEMP -> LINK = NewNode
 8. Exit

11. Insert a Node at middle position
P
link
data
A B
C
D
x
link
link link
data
data
data
start
NewNode
4
3
2
1
Lets consider, POS = 3

12. Algorithm/c to Delete a Node
 1. Input DATA to be deleted
 2. If START is equal to DATA
 TEMP = START
 START = START -> LINK
 Set free node TEMP - which is deleted
 d) Exit
 3. HOLD = START
 4. While ((HOLD -> LINK ->LINK) not equal to NULL)
 a) If(HOLD -> LINK ->DATA) equal to DATA
 i) TEMP = HOLD -> LINK
 ii) HOLD -> LINK = TEMP -> LINK
 iii) Set free node TEMP - which is delete
d
 iv) Exit
 b) HOLD = HOLD -> NEXT

13. Algorithm to Delete a Node
 5. If(HOLD -> LINK ->DATA) equal to DATA
 i) TEMP = HOLD -> LINK
 ii) Set free node TEMP - which is deleted
 iii) HOLD -> LINK = NULL
 iv) Exit
 6. Display DATA not found
 7. Exit

14. Algorithm to Delete a Node
link
data
A B C D
x
link
link link
data
data
data
Node to be deleted
start

15. Single linked List Properties
 Stores a collection of items non-contiguously.
 Each item in the list is stored with an indication of
where the next item is.
 Must know where first item is.
 The list will be a chain of objects, called nodes, of
type Node that contain the data and a reference to
the next Node in the list.
 Allows addition or deletion of items in the middle of
collection with only a constant amount of data mov
ement. Contrast this with array.
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