add doctest/document to actual_power and document to power (TheAlgorithms#11187)

* Update power.py * Update divide_and_conquer/power.py --------- Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>

Author: pedram-mohajer

divide_and_conquer/power.py

@@ -2,6 +2,20 @@ def actual_power(a: int, b: int):
  """
  Function using divide and conquer to calculate a^b.
  It only works for integer a,b.
+
+ :param a: The base of the power operation, an integer.
+ :param b: The exponent of the power operation, a non-negative integer.
+ :return: The result of a^b.
+
+ Examples:
+ >>> actual_power(3, 2)
+ 9
+ >>> actual_power(5, 3)
+ 125
+ >>> actual_power(2, 5)
+ 32
+ >>> actual_power(7, 0)
+ 1
  """
  if b == 0:
  return 1
@@ -13,6 +27,10 @@ def actual_power(a: int, b: int):
 
 def power(a: int, b: int) -> float:
  """
+ :param a: The base (integer).
+ :param b: The exponent (integer).
+ :return: The result of a^b, as a float for negative exponents.
+
  >>> power(4,6)
  4096
  >>> power(2,3)