max_sum_sliding_window.py

"""
Given an array of integer elements and an integer 'k', we are required to find the
maximum sum of 'k' consecutive elements in the array.

Instead of using a nested for loop, in a Brute force approach we will use a technique
called 'Window sliding technique' where the nested loops can be converted to a single
loop to reduce time complexity.
"""

from __future__ importannotations


defmax_sum_in_array(array: list[int], k: int) ->int:
"""
 Returns the maximum sum of k consecutive elements
 >>> arr = [1, 4, 2, 10, 2, 3, 1, 0, 20]
 >>> k = 4
 >>> max_sum_in_array(arr, k)
 24
 >>> k = 10
 >>> max_sum_in_array(arr,k)
 Traceback (most recent call last):
 ...
 ValueError: Invalid Input
 >>> arr = [1, 4, 2, 10, 2, 13, 1, 0, 2]
 >>> k = 4
 >>> max_sum_in_array(arr, k)
 27
 """
iflen(array) <kork<0:
raiseValueError("Invalid Input")
max_sum=current_sum=sum(array[:k])
foriinrange(len(array) -k):
current_sum=current_sum-array[i] +array[i+k]
max_sum=max(max_sum, current_sum)
returnmax_sum


if__name__=="__main__":
fromdoctestimporttestmod
fromrandomimportrandint

testmod()
array= [randint(-1000, 1000) foriinrange(100)]
k=randint(0, 110)
print(
f"The maximum sum of {k} consecutive elements is {max_sum_in_array(array, k)}"
 )