unit 2 First.pptx Searching - Linear and Binary Search

1. SANJIVANI K. B. P. POLYTECHNIC,
KOPARGAON
With NBA ACCREDIATED programs , Approved by AICTE, New Delhi,
Recognized by Govt. of Maharashtra, Affiliated to Maharashtra State Board of
Technical Education, Mumbai, ISO 9001:2015 Certified Institute
Name of Faculty: Prof. Vaibhav A. Parjane
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2. UNIT 2
Searching and Sorting

3. Unit Outcome
After going through this unit, the student will be able to:
2a. Explain working of the given search method with an example.
2b. Write an algorithm to search the given key using binary
Search method
2c. Write an Algorithm to sort data using a specified sorting
method.
2d. Explain the working of given sorting method step by-step with
an example and small data set.

4. Topic to be Covered
Searching
Linear Search
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Sanjivani K. B. P. Polytechnic, Kopargaon Department of Computer Technology Prof. Vaibhav A. Parjane

5. Searching
1. Searching is the process to find the given
element in the list with its position.
2. The search is said to be successful if the given
element is found i.e. the element does exist in
the collection such as an array; other wise it is
unsuccessful.

6. Introduction: (Searching)
• Searching: Searching is a process of finding the
location of a particular element in an array is called
searching.
• There are two types of searching:
 Linear Search:
 Binary Search:

7. Linear Search
• Linear search or sequential search is a method for
finding a particular value in a list that consists of
checking every one of its elements
• One element at a time and in sequence, until the
desired one is found.
• In Linear Search we start searching – sequentially
starting from the first element and continue until
we find the target [ element ] or we are sure that it
is not in the list.
• It is simplest search algorithm

8. Linear Search
• Consider an array of 20 elements.
• Suppose, element 8 is to be search in the array.

9. Linear Search Algorithm
1. Read the total number of array elements in ‘n’, Set
flag = o.
2. Read the ‘n’ array elements in array ‘a’ as – a [o] …
a [n].
3. Read the target to be searched in variable ‘Key’.
4. For i = o to n.
Compare each element of array with ‘Key’ =>
If (a [i] = = Key )
If true then set flag = 1,
and close the loop.
5. Now, if ( flag = = 1) means target found, so print
the location at which target is found.
6. Stop

10. Program:-
# include <stdio.h>
int main ()
{
int a[20],n,i, key , pos , flag = o;
clrscr ();
printf(“n Enter the number of elements in array : n”);
scanf (“% d”, &n);
printf(“n Enter Array element = “);
For (i = o; i < n; i + +)
{
scanf(“%d”, &a[i]);
}
printf(“n Enter the number to search “);
scanf (“%d”, &key);

11. Program:- .. continued
For (i =o; i <n; i + +)
{
if (a[i] == key)
{
pos = i‘;
flag = 1;
break ;
}
}
if (flag == 1 )
printf (“n Element located as %d “n”, pos);
else
printf “n Element not present “);
getch ();
}

12. Linear Search
• The complexity of any searching algorithm depends
on number of comparisons required to find the
element
• Performance of searching algorithm can be found
by counting the number of comparisons in order to
find the given element.

13. Advantages
1. Simple and easy method.
2. Efficient for only small lists.
3. Better for unsorted data.

14. Disadvantage
• Highly inefficient for large data.