Power of two with bitwise operators

Author: edignot

src/bitwise-operator-permissions/bitwise-operator-permissions.js

@@ -19,5 +19,3 @@ export const isNumberPrimeMath = (num) => {
     }
     return true;
 };
-
-console.log(isNumberPrimeMath(4));

src/bitwise-operator-permissions/bitwise-operator-permissions.test.js

@@ -1,11 +1,17 @@
 // Problem: Is given number a power of two?
-// Time complexity: logarithmic O(log n)
 
-const isPowerOfTwo = (num) => {
+// Time complexity: logarithmic O(log n)
+export const isPowerOfTwo = (num) => {
     if (num > 1 && num % 2 === 0) return isPowerOfTwo(num / 2);
     if (num < 1) return false;
     if (num === 1) return true;
     if (num % 2 !== 0) return false;
 };
 
-export default isPowerOfTwo;
+// Utilizing bitwise operators
+// Binary number: 128 64 32 16 8 4 2 1
+// Converting number to binary number - using subtractions 75 -> 01001011
+export const isPowerOfTwoBitwise = (num) => {
+    return num & (num - 1) ? false : true;
+};
+

src/pirmal-numbers/primal-numbers.js

@@ -1,4 +1,4 @@
-import isPowerOfTwo from "./power-of-two";
+import { isPowerOfTwo, isPowerOfTwoBitwise } from "./power-of-two";
 
 describe("Is number a power of two", () => {
     test("Is 8 a power of two", () => {
@@ -11,3 +11,15 @@ describe("Is number a power of two", () => {
         expect(isPowerOfTwo(13)).toBe(false);
     });
 });
+
+describe("Is number a power of two | Bitwise operator", () => {
+    test("Is 8 a power of two", () => {
+        expect(isPowerOfTwoBitwise(8)).toBe(true);
+    });
+    test("Is 24 a power of two", () => {
+        expect(isPowerOfTwoBitwise(24)).toBe(false);
+    });
+    test("Is 13 a power of two", () => {
+        expect(isPowerOfTwoBitwise(13)).toBe(false);
+    });
+});