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

Click here for Explanation

Consider a List displaying below, In this there are 4 nodes. Starting node Start Containing the address of starting node i.e. 2002, and last node containing the null value. Suppose we have search an element=45 in the list

List

Since Start is not null so step 2 will be executed next

Step 2: Ptr=Start=2002 i.e Ptr is now also pointing to the starting node.
Step 3: [Iteration will be started]

Iteration 1: Ptr->Data = 54 is not Equal to Element(=45).
                 so Ptr = Ptr->Next = 2044 [Now Ptr is pointing to next node]

Iteration 2:Ptr->Data = 45 is Equal to Element(=45)
                so Return Success;

Now Suppose we have to search an element=60:


Iteration 1: Ptr->Data = 54 is not Equal to Element(=60).
                 so Ptr = Ptr->Next = 2044 [Now Ptr is pointing to next node]

Iteration 2: Ptr->Data = 45 is not Equal to Element(=60).
                 so Ptr = Ptr->Next = 5260 [Now Ptr is pointing to next node]

Iteration 3: Ptr->Data = 10 is not Equal to Element(=60).
                 so Ptr = Ptr->Next = 3254 [Now Ptr is pointing to next node]

Iteration 4: Ptr->Data = 87 is not Equal to Element(=60).
                 so Ptr = Ptr->Next = null [Now Ptr is now null]

Since Ptr =null now so that Iteration will be finished and Search was failed so
              return FAILURE;