Change project structure to a Maven Java project + Refactor (#2816)

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

@@ -0,0 +1,49 @@
+package com.thealgorithms.maths;
+
+public class BinaryPow {
+
+    /**
+     * Calculate a^p using binary exponentiation
+     * [Binary-Exponentiation](https://cp-algorithms.com/algebra/binary-exp.html)
+     *
+     * @param a the base for exponentiation
+     * @param p the exponent - must be greater than 0
+     * @return a^p
+     */
+    public static int binPow(int a, int p) {
+        int res = 1;
+        while (p > 0) {
+            if ((p & 1) == 1) {
+                res = res * a;
+            }
+            a = a * a;
+            p >>>= 1;
+        }
+        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);
+    }
+}