From 43ee4cc10ce879a0f5a595e9f25da1eb572caa75 Mon Sep 17 00:00:00 2001
From: lakhan_nad <lakhannad1999@gmail.com>
Date: Sun, 25 Oct 2020 15:16:25 +0530
Subject: [PATCH 1/3] Added Binary Exponentiation Fixes:#1943

---
 Maths/BinaryPow.java | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Maths/BinaryPow.java

diff --git a/Maths/BinaryPow.java b/Maths/BinaryPow.java
new file mode 100644
index 000000000000..5e66d8947a94
--- /dev/null
+++ b/Maths/BinaryPow.java
@@ -0,0 +1,31 @@
+package 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;
+  }
+
+  /** Test Functions */
+  public static void main(String[] args) {
+    int a = 2;
+    int p = 15;
+    int res = BinPow(a, p);
+    System.out.println(a + "^" + p + ": " + res);
+  }
+}

From 25300c1c0a163bd247bc8245083419c67d813234 Mon Sep 17 00:00:00 2001
From: lakhan_nad <lakhannad1999@gmail.com>
Date: Sun, 15 Nov 2020 23:46:23 +0530
Subject: [PATCH 2/3] tests added in Binary Exponentation #1945

---
 Maths/BinaryPow.java | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/Maths/BinaryPow.java b/Maths/BinaryPow.java
index 5e66d8947a94..e7f931488cba 100644
--- a/Maths/BinaryPow.java
+++ b/Maths/BinaryPow.java
@@ -9,7 +9,7 @@ public class BinaryPow {
    * @param p the exponent - must be greater than 0
    * @return a^p
    */
-  public static int BinPow(int a, int p) {
+  public static int binPow(int a, int p) {
     int res = 1;
     while (p > 0) {
       if ((p & 1) == 1) {
@@ -21,11 +21,25 @@ public static int BinPow(int a, int p) {
     return res;
   }
 
-  /** Test Functions */
-  public static void main(String[] args) {
-    int a = 2;
-    int p = 15;
-    int res = BinPow(a, p);
+  /** 
+   * 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);
     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);
+  }
 }

From 1f1893abe489c99383240bd4ac252d4215ebb709 Mon Sep 17 00:00:00 2001
From: lakhan_nad <lakhannad1999@gmail.com>
Date: Sun, 15 Nov 2020 23:52:33 +0530
Subject: [PATCH 3/3] Assertion Added

---
 Maths/BinaryPow.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Maths/BinaryPow.java b/Maths/BinaryPow.java
index e7f931488cba..d3224c8bcf41 100644
--- a/Maths/BinaryPow.java
+++ b/Maths/BinaryPow.java
@@ -28,6 +28,7 @@ public static int binPow(int a, int p) {
    */
   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);
   }