1. Title: Programs based on linked list.
Introduction:
The linked allocation method of storage is more suitable for much computer application. It can
result in both the efficient use of computer storage and computer time. It has following
characteristics:
1. Unpredictable storage requirement
2. Extensive manipulation of data stored
Linked List: A linked list or one way list or chain list is a linear collection of data elements
called node where the linear order is given by means of pointer. Each node is divided into
two parts:
1. Information of the elements.
2. Address of the next node in the list called as linked field or next pointer field. The
pointer of the last node contains a special value called null pointer which is an invalid
address. In actual practice, 0 or negative number is used for null pointer.
Important concepts related to Linked List:
Node: Each item in the list is called a node and contains two fields such as:
1. Information field
2. Next address field
1. Information field: The Information field holds the actual elements on the list.
2. Next address field: The Next address field contains the address of the next node in
the list.
Pointer and Null pointer: The address which is used to access a particular node is known
as a pointer. The entire linked list is accessed from an external pointer list that points to
the first node in the list. The next address of the last node in the list contains a special
value, known as null, which is not valid address. This null pointer is used to signal the
end of the list.
Empty list: The list with no nodes on it is called empty list or null list. The value of the
external pointer list to such a list is the null pointer. A list can be initialize to the empty
list by the operation list=null.

2. Operations on linked list:
1. Searching
2. Insertion
3. Deletion
1. Searching for node from linked list
Algorithm: Search_node(Start, Data)
[Searches for data, start ptr to first node]
Step 1: Start
Step 2: Accept linked list and data
Step 3: Set temp=Start
Step 4: While link [temp] not equal to Null [check till end]
If info [temp] =Data, then
Write: “Found Successfully”
Exit [if found, stop]
[End of if]
Set Temp=Link [tamp] [pointer is incremented to next]
[End of while]
Step 5: Write: “Not Found”
Step 6: Exit [stop]
Types of linked list:
1. Linear
2. Doubly
3. Circular
1. Linear linked list
Contained within itself the address of the next items such an explicit ordering gives rise to a data
structure, which is known as a linear linked list.

3. info Next Node
2. Doubly linked list
In a doubly linked list, each node contains, besides the next-node link, a second link field
pointing to the previous node in the sequence. The two links may be called forward(s) and
backwards, or next and previous.
Head address to next node last
Address to previous node
3. Circular
Circular list
In a circularly linked list, all nodes are linked in a continuous circle, without using null. For lists
with a front and a back (such as a queue), one stores a reference to the last node in the list. The
next node after the last node is the first node. Elements can be added to the back of the list and
removed from the front in constant time.
Circularly linked lists can be either singly or doubly linked.
Both types of circularly linked lists benefit from the ability to traverse the full list beginning at
any given node. This often allows us to avoid storing firstNode and lastNode, although if the list
may be empty we need a special representation for the empty list, such as a lastNode variable
which points to some node in the list or is null if it's empty; we use such a lastNode here. This
representation significantly simplifies adding and removing nodes with a non-empty list, but
empty lists are then a special case.
First node last node

4. Advantages of linked list :
1. Linked list is an example of dynamic data structure
2. Linked list can be grow and shrink during execution of the program
3. It allows to use memory efficiently the memory is not allocated in advance so according to
need,memory can be allocated
4. Representation of the linear data structure can be easily implement using it.
5. Memory is freed whenever there is no need of it.
6. Insertion and deletion are efficient and easy.