find the sum of subarrays of size k code example

Example: minimum subarray size with sum >k

def smallestSubWithSum(arr, n, x):
 
    # Initialize current sum and minimum length
    curr_sum = 0
    min_len = n + 1
 
    # Initialize starting and ending indexes
    start = 0
    end = 0
    while (end < n):
 
        # Keep adding array elements while current
        # sum is smaller than or equal to x
        while (curr_sum <= x and end < n):
            curr_sum += arr[end]
            end += 1
 
        # If current sum becomes greater than x.
        while (curr_sum > x and start < n):
 
            # Update minimum length if needed
            if (end - start < min_len):
                min_len = end - start
 
            # remove starting elements
            curr_sum -= arr[start]
            start += 1
 
    return min_len