sorted search increase performance

Question

Running through exercises on testdome...currently looking at https://www.testdome.com/for-developers/solve-question/9877

Implement function CountNum

Answer 1

If you like to implement your own BST, you can try the following code. It is written in Python. You can rewrite it in other languages if required. It passes all the 4 tests.

def count_numbers(sorted_list, less_than):

    if len(sorted_list) == 0 or sorted_list[0] >= less_than:
        return 0
    if sorted_list[-1] < less_than:
        return len(sorted_list)

    arr = sorted_list
    def lt_array(low, high, arr):
        mid = low + (high-low+1) //2 
        if arr[mid] >= less_than and arr[mid-1] < less_than:
            return mid
        if arr[mid] > less_than:
            return lt_array(low,mid,arr)
        else:
            return lt_array(mid, high, arr)
    
    return lt_array(0,len(sorted_list)-1, arr)