Binary Search

 

Binary Search

Algorithm: Binary Search

Input: A list of sorted elements and the element to be searched.

Output: Position of the element if found, otherwise a message saying that the element is not found.

Steps:

§  Start the process.

§  Read the list of elements.

§  Sort the list in ascending order.

§  Read the element that needs to be searched.

§  Set bottom to the first index of the list.

§  Set top to the last index of the list.

§  Repeat the following steps until the search ends:

o  If bottom becomes greater than top, display that the element is not found and stop.

o  Find the middle position.

o  If the middle element is equal to the search element, display the position and stop.

o  If the middle element is smaller than the search element, search in the right half by changing bottom to mid + 1.

o  If the middle element is larger than the search element, search in the left half by changing top to mid - 1.

§  End the process.

 

 # Binary Search

def BinarySearch(L,ele):

bottom = 0

top = len(L)-1

while(True):

if (bottom > top):

print("Element not found")

return

   

mid = (bottom+top)//2

    

if(L[mid] == ele):

print("Element", ele, "present at position", mid+1)

return

elif (L[mid] < ele):

bottom = mid + 1

else:

top = mid - 1

L = eval(input("Enter list of elements : "))

L.sort()

ele = eval(input("Enter element to search : "))

BinarySearch(L,ele)