This document describes and compares linear search and binary search algorithms. It contains the following key points: 1) Linear search sequentially checks each element of a list one-by-one until the target element is found. It is simple but inefficient, especially for large lists. 2) Binary search works on a sorted list by checking the middle element first. It then eliminates half of the remaining list and searches the other half recursively until the target is found. It is more efficient than linear search for large sorted lists. 3) Pseudocode algorithms are provided for both linear search and binary search to illustrate the search process step-by-step.

1. Searching
• Fundamental operation in data structure
• The process of finding a specific data item or
record from a list is called searching
– Fast searching important task ,other operation
insertion deletion depends on this
– It is successful if the record is found other wise fail
• Different technique are use as
– Sequential search
– Binary search

2. Linear Search
• The Linear Search, or sequential search, is
simply examining each element in a list one by
one until the desired element is found.
– The Linear Search is not very efficient.
• It start from the first element in the list to the last element and
compare the required item with each one by one why it is
called Linear search
– It is a slow process
– Used for small amount of data
• Its algorithm and its implementation is as

3. Algorithm for Linear Search
Algorithm to find a value ITEM from an array ABC
consisting of N elements
1. SET LOC=-1
2. [Enter value that has to be serched]
INPUT ITEM
3. REPEAT STEP 4 FOR I=1 TO N
4. IF ITEM=ABC[I]
LOC=I
PRINT” data found at location ”LOC
EXIT
END IF
[END LOOP]
5. IF LOC=-1
PRINT “item not Found”
exit
END IF

4. Binary Search
• Efficient technique to search a specific item from
a list of items
• Used for large list of data that are sorted in
ascending or descending order
– It searches from the middle of the list , if the list is
sorted in ascending order and the required value is
greater than the value at the middle , the control goes
to the higher value next to middle value that become
min now
– If the required value is less than the middle value then
the control goes to the lesser value previous to middle
value that become max now
– This process is continue till value found
• If value found it is successful otherwise
unsuccessful

5. Algorithm for Binary Search
• Algorithm to find a value ITEM in array ABC
,consist of N elements in sorted order LOC hold
the position of the element that has the required
value , MID variable to hold the position of the
middle of the array
• For this to find MID
– MID =(1+N)/2
– This add first and last script value and find its average
the whole integer script is taken the middle

6. 1. SET LOC=-1
2. [enter value to search]
INPUT ITEM
3. MID=(1+N)/2
4. IF ITEM=ABC[MID] THEN
Loc=MID
PRINT" value found at middle”
EXIT
END IF
5. [search towards right]
If ITEM>ABC[MID]
]THEN
REPEAT FOR I=MID+1 TO N BY 1
IF ITEM=ABC[I] THEN
Loc=I
PRINT “VALUE AT POSITION”,I
EXIT
END IF
ELSE [check toward left]
REPEAT FOR I=MID-1 TO 1 BY -1
IF ITEM=ABC[I] THEN
Loc=I
PRINT” value at position ”,I
END IF
IF LOC=-1 THEN
PRINT “Data not found”
EXIT
END IF