only singly link list

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.
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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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