#### CBSE Class 12 : Data Structures

Introduction to Data Structures

#### CBSE Class 12 : Searching

Creation And Traversal
What is Searching?
Linear/Sequential Search
Binary Search
Insertion Of Element
Deletion Of Element

What is sorting?
Bubble Sort
Selection Sort
Insertion Sort

# Class 12: Data Structures Searching 5

Example:1
Write a python script to search an element with in a list using Binary Search.
Sol:

```def binary_search(arr, x):
low = 0
high = len(arr) - 1
mid = 0

while low <= high:

mid = (high + low) // 2

# Check if x is present at mid
if arr[mid] < x:
low = mid + 1

# If x is greater, ignore left half
elif arr[mid] > x:
high = mid - 1

# If x is smaller, ignore right half
else:
return mid

# If we reach here, then the element was not present
return -1

#-- main --
#arr is a list containing elements
arr = [ 2, 3, 4, 10, 40 ]
# x : element to search
x = 4

# Function call
result = binary_search(arr, x)
if result != -1:
print("Element is present at index", str(result+1))
else:
print("Element is not present in array") ```

Output:

Case:1

`Element is present at index 3`

Important Pages