From d6364548aa2a1e3e4d58a27dbfb6752eec8d9029 Mon Sep 17 00:00:00 2001
From: Indre Maksimovaite <imaksimovaite@gmail.com>
Date: Mon, 11 Oct 2021 20:24:38 +0300
Subject: [PATCH] Check if number is already power of two

---
 Bit-Manipulation/NextPowerOfTwo.js           | 3 +++
 Bit-Manipulation/test/NextPowerOfTwo.test.js | 6 +++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/Bit-Manipulation/NextPowerOfTwo.js b/Bit-Manipulation/NextPowerOfTwo.js
index b5999252f..623469e4d 100644
--- a/Bit-Manipulation/NextPowerOfTwo.js
+++ b/Bit-Manipulation/NextPowerOfTwo.js
@@ -2,10 +2,13 @@
  *
  *  This script will find next power of two
  *    of given number.
+ *  More about it:
+ *   https://www.techiedelight.com/round-next-highest-power-2/
  *
  */
 
 export const nextPowerOfTwo = (n) => {
+  if (n > 0 && (n & (n - 1)) === 0) return n
   let result = 1
   while (n > 0) {
     result = result << 1
diff --git a/Bit-Manipulation/test/NextPowerOfTwo.test.js b/Bit-Manipulation/test/NextPowerOfTwo.test.js
index 271b08249..073224046 100644
--- a/Bit-Manipulation/test/NextPowerOfTwo.test.js
+++ b/Bit-Manipulation/test/NextPowerOfTwo.test.js
@@ -4,12 +4,12 @@ describe('NextPowerOfTwo', () => {
   it.each`
     input    | result
     ${0}     | ${1}
-    ${1}     | ${2}
-    ${2}     | ${4}
+    ${1}     | ${1}
+    ${2}     | ${2}
     ${3}     | ${4}
     ${5}     | ${8}
     ${125}   | ${128}
-    ${1024}  | ${2048}
+    ${1024}  | ${1024}
     ${10000} | ${16384}
   `('returns $result when is given $input', ({ input, result }) => {
     const res = nextPowerOfTwo(input)