Binary search - find the right border

find_right_border.py

def find_right_border(arr, target):
    left = 0
    right = len(arr) - 1

    right_border = -1       # keep track of the latest larger number
    while left <= right:
        mid = left + (right - left) // 2
        if arr[mid] <= target:
            left = mid + 1
        else:
            right_border = mid
            right = mid - 1

    return right_border