Python: Binary search

Python Search and Sorting : Exercise-1 with Solution

Write a Python program for binary search.
Binary Search : In computer science, a binary search or half-interval search algorithm finds the position of a target value within a sorted array. The binary search algorithm can be classified as a dichotomies divide-and-conquer search algorithm and executes in logarithmic time.

Step by step example :

Binary search Part - 1

Binary search Part - 2

Binary search Part - 3

Binary search Part - 4

Sample Solution:

Python Code:

def binary_search(item_list,item):
	first = 0
	last = len(item_list)-1
	found = False
	while( first<=last and not found):
		mid = (first + last)//2
		if item_list[mid] == item :
			found = True
			if item < item_list[mid]:
				last = mid - 1
				first = mid + 1	
	return found
print(binary_search([1,2,3,5,8], 6))
print(binary_search([1,2,3,5,8], 5))

Sample Output:



Flowchart: Python Data Structures and Algorithms: Binary search

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Python: Tips of the Day

Enum Class:

Here is another classy approach from Python, no pun intended. Python's enum class will let you create enum object members with constant and unique values which then can be listed, compared or used for identification.

Enum classes are also iterable so they can be iterated as well:

from enum import Enum
class sports(Enum):
    volleyball = 1
    soccer = 2
    running = 3
    football = 4
    baseball = 5
    boxing = 6


<sports.baseball: 5>