Question

How to find the first occurrence of an element inside sorted list using binary search in Python

Answer 1

from bisect import bisect_left 
 
def binary_search(lst, n): 
    i = bisect_left(lst, n) 
    if i != len(lst) and lst[i] == n:
        return i 
    else: 
        return -1
  
lst = [1, 2, 3, 3, 3, 4, 20, 40]
 
result = binary_search(lst, 3) 
if result == -1: 
    print("Element not Found") 
else: 
    print("Element found at index", result)
 
  
  
  
  
'''
run:
  
Element found at index 2
  
'''

 

70+ SQL courses for beginners and professionals