Enhance code density and readability (TheAlgorithms#4914)

Hardvan · vil02 · web-flow · commit d086afce09a7 · 2023-10-30T23:18:05.000+01:00
* Enhance code density and readability

* Add wiki link

---------

Co-authored-by: vil02 &lt;65706193+vil02@users.noreply.github.com&gt;
diff --git a/src/main/java/com/thealgorithms/divideandconquer/BinaryExponentiation.java b/src/main/java/com/thealgorithms/divideandconquer/BinaryExponentiation.java
@@ -2,6 +2,8 @@
 
 // Java Program to Implement Binary Exponentiation (power in log n)
 
+// Reference Link: https://en.wikipedia.org/wiki/Exponentiation_by_squaring
+
 /*
  * Binary Exponentiation is a method to calculate a to the power of b.
  * It is used to calculate a^n in O(log n) time.
@@ -14,14 +16,14 @@ public class BinaryExponentiation {
 
     // recursive function to calculate a to the power of b
     public static long calculatePower(long x, long y) {
+        // Base Case
         if (y == 0) {
             return 1;
         }
-        long val = calculatePower(x, y / 2);
-        if (y % 2 == 0) {
-            return val * val;
+        if (y % 2 == 1) { // odd power
+            return x * calculatePower(x, y - 1);
         }
-        return val * val * x;
+        return calculatePower(x * x, y / 2); // even power
     }
 
     // iterative function to calculate a to the power of b
