feat: add prime factorization algorithm

Maths/PrimeFactorization.js

@@ -0,0 +1,29 @@
+/**
+ * @function primeFactorization
+ * @description Returns all prime factors of a given positive integer.
+ *   Prime factorization is the process of determining which prime numbers
+ *   multiply together to make the original number.
+ * @param {number} n - A positive integer greater than 1
+ * @returns {number[]} - An array of prime factors in ascending order
+ * @see https://en.wikipedia.org/wiki/Integer_factorization
+ * @example primeFactorization(12) => [2, 2, 3]
+ * @example primeFactorization(28) => [2, 2, 7]
+ * @example primeFactorization(13) => [13]
+ */
+const primeFactorization = (n) => {
+  if (!Number.isInteger(n) || n < 2) {
+    throw new TypeError('Input must be an integer greater than or equal to 2')
+  }
+  const factors = []
+  let num = n
+  for (let i = 2; i <= Math.sqrt(num); i++) {
+    while (num % i === 0) {
+      factors.push(i)
+      num = Math.floor(num / i)
+    }
+  }
+  if (num > 1) factors.push(num)
+  return factors
+}
+
+export { primeFactorization }

Maths/test/PrimeFactorization.test.js

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+import { primeFactorization } from '../PrimeFactorization.js'
+
+describe('primeFactorization', () => {
+  test('primeFactorization(2) returns [2]', () => {
+    expect(primeFactorization(2)).toEqual([2])
+  })
+
+  test('primeFactorization(12) returns [2, 2, 3]', () => {
+    expect(primeFactorization(12)).toEqual([2, 2, 3])
+  })
+
+  test('primeFactorization(28) returns [2, 2, 7]', () => {
+    expect(primeFactorization(28)).toEqual([2, 2, 7])
+  })
+
+  test('primeFactorization(13) returns [13]', () => {
+    expect(primeFactorization(13)).toEqual([13])
+  })
+
+  test('primeFactorization(100) returns [2, 2, 5, 5]', () => {
+    expect(primeFactorization(100)).toEqual([2, 2, 5, 5])
+  })
+
+  test('primeFactorization(360) returns [2, 2, 2, 3, 3, 5]', () => {
+    expect(primeFactorization(360)).toEqual([2, 2, 2, 3, 3, 5])
+  })
+
+  test('primeFactorization of a prime returns that prime', () => {
+    expect(primeFactorization(97)).toEqual([97])
+  })
+
+  test('throws TypeError for 1', () => {
+    expect(() => primeFactorization(1)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for negative input', () => {
+    expect(() => primeFactorization(-12)).toThrow(TypeError)
+  })
+
+  test('throws TypeError for float input', () => {
+    expect(() => primeFactorization(12.5)).toThrow(TypeError)
+  })
+})