Add test case to BinaryPow Algorithm (#3177)

Co-authored-by: Yang Libin <contact@yanglibin.info>

src/main/java/com/thealgorithms/maths/BinaryPow.java

@@ -21,29 +21,4 @@ public class BinaryPow {
         }
         return res;
     }
-
-    /**
-     * Function for testing binary exponentiation
-     *
-     * @param a the base
-     * @param p the exponent
-     */
-    public static void test(int a, int p) {
-        int res = binPow(a, p);
-        assert res == (int) Math.pow(a, p) : "Incorrect Implementation";
-        System.out.println(a + "^" + p + ": " + res);
-    }
-
-    /**
-     * Main Function to call tests
-     *
-     * @param args System Line Arguments
-     */
-    public static void main(String[] args) {
-        // prints 2^15: 32768
-        test(2, 15);
-
-        // prints 3^9: 19683
-        test(3, 9);
-    }
 }

src/test/java/com/thealgorithms/maths/BinaryPowTest.java

@@ -0,0 +1,16 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class BinaryPowTest {
+
+    @Test
+    void testBinPow() {
+        assertEquals(4, BinaryPow.binPow(2, 2));
+        assertEquals(256, BinaryPow.binPow(4, 4));
+        assertEquals(729, BinaryPow.binPow(9, 3));
+        assertEquals(262144, BinaryPow.binPow(8, 6));
+    }
+}