feat: add isPowerOfTwo algorithm

Maths/IsPowerOfTwo.js

@@ -0,0 +1,20 @@
+/**
+ * @function isPowerOfTwo
+ * @description Checks whether a given positive integer is a power of two.
+ *   A number is a power of two if it can be expressed as 2^n where n
+ *   is a non-negative integer. Uses bitwise AND for efficient checking.
+ * @param {number} n - A positive integer
+ * @returns {boolean} - True if n is a power of two, false otherwise
+ * @see https://en.wikipedia.org/wiki/Power_of_two
+ * @example isPowerOfTwo(1) => true
+ * @example isPowerOfTwo(16) => true
+ * @example isPowerOfTwo(18) => false
+ */
+const isPowerOfTwo = (n) => {
+  if (!Number.isInteger(n) || n < 1) {
+    throw new TypeError('Input must be a positive integer')
+  }
+  return (n & (n - 1)) === 0
+}
+
+export { isPowerOfTwo }

Maths/test/IsPowerOfTwo.test.js

@@ -0,0 +1,47 @@
+import { isPowerOfTwo } from '../IsPowerOfTwo.js'
+
+describe('isPowerOfTwo', () => {
+  test('1 is a power of two (2^0)', () => {
+    expect(isPowerOfTwo(1)).toBe(true)
+  })
+
+  test('2 is a power of two (2^1)', () => {
+    expect(isPowerOfTwo(2)).toBe(true)
+  })
+
+  test('4 is a power of two (2^2)', () => {
+    expect(isPowerOfTwo(4)).toBe(true)
+  })
+
+  test('16 is a power of two (2^4)', () => {
+    expect(isPowerOfTwo(16)).toBe(true)
+  })
+
+  test('1024 is a power of two (2^10)', () => {
+    expect(isPowerOfTwo(1024)).toBe(true)
+  })
+
+  test('3 is NOT a power of two', () => {
+    expect(isPowerOfTwo(3)).toBe(false)
+  })
+
+  test('18 is NOT a power of two', () => {
+    expect(isPowerOfTwo(18)).toBe(false)
+  })
+
+  test('100 is NOT a power of two', () => {
+    expect(isPowerOfTwo(100)).toBe(false)
+  })
+
+  test('throws TypeError for zero', () => {
+    expect(() => isPowerOfTwo(0)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for negative input', () => {
+    expect(() => isPowerOfTwo(-4)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for float input', () => {
+    expect(() => isPowerOfTwo(4.5)).toThrow(TypeError)
+  })
+})