Add the Collatz Conjecture

Maths/CollatzSequence.js

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+/**
+ * @function collatz
+ * @description Applies the Collatz Sequence on a specified number.
+ * The Collatz Sequence states that every natural number will always fall in a 1, 2, 4 loop when iterated under the following function:
+ * If the number is even, divide by 2, and if its odd, multiply it by 3 and add 1.
+ *
+ * @parama {Integer} n The number to apply the Collatz Sequence to.
+ *
+ * @return An array of steps and the final result..
+ *
+ * @see [Collatz Conjecture](https://en.wikipedia.org/wiki/Collatz_conjecture)
+ *
+ * @example collatz(1) = { result: 1, steps: [] }
+ * @example collatz(5) = { result: 1, steps: [16, 8, 4, 2, 1] }
+*/
+export function collatz (n) {
+  const steps = []
+
+  while (n !== 1) {
+    if (n % 2 === 0) {
+      n = n / 2
+    } else {
+      n = 3 * n + 1
+    }
+
+    steps.push(n)
+  }
+
+  return { result: n, steps: steps }
+}

Maths/test/CollatzSequence.test.js

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+import { collatz } from '../CollatzSequence'
+
+describe('The Collatz Sequence', () => {
+  it('Should be 1', () => {
+    expect(collatz(1)).toStrictEqual({ result: 1, steps: [] })
+    expect(collatz(5)).toStrictEqual({ result: 1, steps: [16, 8, 4, 2, 1] })
+  })
+})