Solution: Search in a Rotated List

def pivoted_binary_search(lst, n, key):
    """
    Function to search key in a list
    :param lst: A list of integers
    :param n: The size of the list
    :param key: A key to be searched in the list
    """
    pivot = find_pivot_point(lst, 0, n - 1)
    # If the list is not rotated
    if pivot == -1:
        return binary_search(lst, 0, n - 1, key)
    # If the list is rotated then find the elements in left sided and right sided list
    if lst[pivot] == key:
        return pivot
    if lst[0] <= key:
        return binary_search(lst, 0, pivot - 1, key)
    return binary_search(lst, pivot + 1, n - 1, key)
def find_pivot_point(lst, low, high):
    """
    Function to pivot in the list
    :param lst: A list of integers
    :param low: Lowest index of the list
    :param high: Highest index of the list
    """
    # base cases
    if high < low:
        return -1
    if high == low:
        return low
    mid = (low + high) // 2
    if mid < high and lst[mid] > lst[mid + 1]:
        return mid
    if mid > low and lst[mid] < lst[mid - 1]:
        return mid - 1
    if lst[low] >= lst[mid]:
        return find_pivot_point(lst, low, mid - 1)
    return find_pivot_point(lst, mid + 1, high)
def binary_search(lst, low, high, key):
    """
    Binary Search function
    :param lst: A list of integers
    :param low: Lowest index of the list
    :param high: Highest index of the list
    :param key: A key to be searched in the list
    """
    if high < low:
        return -1
    mid = (low + high) // 2
    if key == lst[mid]:
        return mid
    if key > lst[mid]:
        return binary_search(lst, (mid + 1), high, key)
    return binary_search(lst, low, (mid - 1), key)
# Driver to test above code
if __name__ == '__main__':
    lst = [6, 7, 8, 9, 10, 0, 1, 2, 3]
    key = 0
    print("Index of the element is : ",
          pivoted_binary_search(lst, len(lst), key))