Added Finding Exponent Program (TheAlgorithms#2238)

* Finding Exponent Program

* Build Error Fix - 1

* Build Error Fix - 2

* Error Fix - 1 datatype

* self-documenting naming convension added

* Update and rename exponent_recursion.py to power_using_recursion.py

* Fix typo

* Fix typo

Co-authored-by: Christian Clauss <[email protected]>

Author: 2 people

Diff for: maths/power_using_recursion.py

@@ -0,0 +1,36 @@
+"""
+== Raise base to the power of exponent using recursion ==
+    Input -->
+        Enter the base: 3
+        Enter the exponent: 4
+    Output  -->
+        3 to the power of 4 is 81
+    Input -->
+        Enter the base: 2
+        Enter the exponent: 0
+    Output -->
+        2 to the power of 0 is 1
+"""
+
+
+def power(base: int, exponent: int) -> float:
+    """
+    power(3, 4)
+    81
+    >>> power(2, 0)
+    1
+    >>> all(power(base, exponent) == pow(base, exponent)
+    ...     for base in range(-10, 10) for exponent in range(10))
+    True
+    """
+    return base * power(base, (exponent - 1)) if exponent else 1
+
+
+if __name__ == "__main__":
+    print("Raise base to the power of exponent using recursion...")
+    base = int(input("Enter the base: ").strip())
+    exponent = int(input("Enter the exponent: ").strip())
+    result = power(base, abs(exponent))
+    if exponent < 0:  # power() does not properly deal w/ negative exponents
+        result = 1 / result
+    print(f"{base} to the power of {exponent} is {result}")