Algorithm to search element in the Linked list

Search_LL(List, element, Start)

Here, List is a Linked list containing n elements, in which we have to search element. Start is a pointer which is containing the address of starting Node. SUCCESS=1 is a constant which will be returned on successful search and FAILURE=0 is a constant which will be returned on unsuccessful search. Ptr is a intermediate pointer which is used to traverse the list.

Step 1: [check, if list is empty]

            If Start = null then 

                   return FAILURE;

Step 2: Ptr = Start

Step 3: While Ptr < > null repeat step 4

Step 4: i) If Ptr -> Data = Element then 

                    return SUCCESS;

           ii) Ptr = Ptr->Next

Step 5: return FAILURE;

Step 6: End

Algorithm to insert node in Simple Linked List

Insert_LinkedList ( List, Node, Start, Value,Data)

In this algorithm List is a linked list having n nodes. Start is a pointer which contains the address of starting node of the list.Node  is the pointer pointing to the new node. Value is the data of a node from list after which the new node is to be inserted.Data is the value which is to be assigned to the data part of new node.

Node->data contains data and Node->Next points next node. In this algorithm following criteria are followed.

• If List is empty Node will be inserted at starting of list
• If Value found in the list than node will be inserted after the value
• else node will be inserted at the end of list

Ptr is an intermediate pointer which points the current node and used to traverse the list

Step 1: i) Node ->data = Data

Step 2: [Check if list is empty then we will insert new node at the starting point.]

            If Start = null then go to step 3 else go to step 4

Step 3: i) Node->Next=null.

            ii) Start=Node

            iii) Return

Step 4: [assigning the 1st node address to Ptr]

                  Ptr = Start

Step 5: While Ptr->Next is Not null repeat

            i) if Ptr->data = Data then go to step i.a else go to step ii)

                     a) Node->Next = Ptr->Next

                     b) Ptr->Next = Node

                     c) Return

           ii) Ptr = Ptr->Next

Step 6: [If Value that was searched not found, in that case inserting Node at the end of List]

            i)Node->Next = null

           ii)Ptr->Next = Node

Step 7: End

Linked List

Definition

A Linked List is a linear collection of data element(where linearity is achieved by pointers in node) with following properties:.

1. Each element of Linked list is called Node
2. There is a pointer called start. Which contains address of first Node
3. Each Node has atleast two part. 1st is data part another is pointer part. Data part contains actual data. and pointer part contains address of next Node.
4. Pointer of Last Node of Linked List contains null.

Types of Linked List

1. Simple Linked List
2. Header Linked List
3. Circular Linked List
4. Two way Linked List
5. Hybrid Linked List