Add leastCommonMultipleArray function and corresponding tests

src/algorithms/math/least-common-multiple/__test__/leastCommonMultiple.test.js

@@ -1,4 +1,4 @@
-import leastCommonMultiple from '../leastCommonMultiple';
+import leastCommonMultiple, { leastCommonMultipleArray } from '../leastCommonMultiple';
 
 describe('leastCommonMultiple', () => {
   it('should find least common multiple', () => {
@@ -15,4 +15,14 @@ describe('leastCommonMultiple', () => {
     expect(leastCommonMultiple(-7, -9)).toBe(63);
     expect(leastCommonMultiple(-7, 9)).toBe(63);
   });
+
+  it('should find least common multiple of an array', () => {
+    expect(leastCommonMultipleArray([4, 6])).toBe(12);
+    expect(leastCommonMultipleArray([6, 21, 14])).toBe(42);
+    expect(leastCommonMultipleArray([3, 5, 7])).toBe(105);
+    expect(leastCommonMultipleArray([2, 3, 5, 7, 11])).toBe(2310);
+    expect(leastCommonMultipleArray([1000000, 2, 3])).toBe(3000000);
+    expect(leastCommonMultipleArray([-9, -18, -27])).toBe(54);
+    expect(leastCommonMultipleArray([7, -9, 3])).toBe(63);
+  });
 });

src/algorithms/math/least-common-multiple/leastCommonMultiple.js

@@ -5,7 +5,14 @@ import euclideanAlgorithm from '../euclidean-algorithm/euclideanAlgorithm';
  * @param {number} b
  * @return {number}
  */
-
 export default function leastCommonMultiple(a, b) {
   return ((a === 0) || (b === 0)) ? 0 : Math.abs(a * b) / euclideanAlgorithm(a, b);
 }
+
+/**
+ * @param {number[]} numbers
+ * @return {number}
+ */
+export function leastCommonMultipleArray(numbers) {
+  return numbers.reduce((acc, val) => leastCommonMultiple(acc, val), 1);
+}