Add problem 50 - Pow (x, n)

Author: anirudhology

problems/math/pow_xn.py

@@ -0,0 +1,7 @@
+class PowXN:
+    def myPow(self, x: float, n: int) -> float:
+        if n == 0:
+            return 1
+        if n < 0:
+            return 1 / x * self.myPow(1 / x, -n - 1)
+        return self.myPow(x * x, n // 2) if n % 2 == 0 else x * self.myPow(x * x, n // 2)

tests/math/pow_xn_test.py

@@ -0,0 +1,37 @@
+import unittest
+
+from problems.math.pow_xn import PowXN
+
+
+class TestPowXN(unittest.TestCase):
+
+    def setUp(self):
+        self.pow_xn = PowXN()
+
+    def test_power_zero_exponent(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(2.0, 0), 1.0, places=5)
+
+    def test_power_negative_exponent(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(2.0, -2), 0.25, places=5)
+
+    def test_power_positive_exponent_even(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(2.0, 4), 16.0, places=5)
+
+    def test_power_positive_exponent_odd(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(2.0, 3), 8.0, places=5)
+
+    def test_power_base_zero(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(0.0, 5), 0.0, places=5)
+
+    def test_power_base_one(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(1.0, 5), 1.0, places=5)
+
+    def test_power_base_negative_one_odd(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(-1.0, 3), -1.0, places=5)
+
+    def test_power_base_negative_one_even(self):
+        self.assertAlmostEqual(self.pow_xn.myPow(-1.0, 2), 1.0, places=5)
+
+
+if __name__ == '__main__':
+    unittest.main()