Add tests for power using recursion algorithm (TheAlgorithms#4335)

BamaCharanChhandogi · web-flow · commit 80a443503895 · 2023-08-28T07:03:27.000Z
diff --git a/src/main/java/com/thealgorithms/maths/PowRecursion.java b/src/main/java/com/thealgorithms/maths/PowRecursion.java
diff --git a/src/main/java/com/thealgorithms/maths/PowerUsingRecursion.java b/src/main/java/com/thealgorithms/maths/PowerUsingRecursion.java
@@ -0,0 +1,20 @@
+package com.thealgorithms.maths;
+
+/**
+ * calculate Power using Recursion
+ * @author Bama Charan Chhandogi (https://github.com/BamaCharanChhandogi)
+ */
+
+public class PowerUsingRecursion {
+
+    public static double power(double base, int exponent) {
+        // Base case: anything raised to the power of 0 is 1
+        if (exponent == 0) {
+            return 1;
+        }
+
+        // Recursive case: base ^ exponent = base * base ^ (exponent - 1)
+        // Recurse with a smaller exponent and multiply with base
+        return base * power(base, exponent - 1);
+    }
+}
diff --git a/src/test/java/com/thealgorithms/maths/PowerUsingRecursionTest.java b/src/test/java/com/thealgorithms/maths/PowerUsingRecursionTest.java
@@ -0,0 +1,20 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test case for Power using Recursion
+ * @author Bama Charan Chhandogi (https://github.com/BamaCharanChhandogi)
+ */
+
+class PowerUsingRecursionTest {
+
+    @Test
+    void testPowerUsingRecursion() {
+        assertEquals(32.0, PowerUsingRecursion.power(2.0, 5));
+        assertEquals(97.65625, PowerUsingRecursion.power(2.5, 5));
+        assertEquals(81, PowerUsingRecursion.power(3, 4));
+    }
+}
