Added LCM for Array

Author: mukund1606

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

@@ -0,0 +1,24 @@
+import leastCommonMultipleArray from '../leastCommonMultipleArray';
+
+describe('leastCommonMultiple', () => {
+  it('should find least common multiple', () => {
+    expect(() => leastCommonMultipleArray([])).toThrow(Error('Array is empty'));
+    expect(leastCommonMultipleArray([0, 0])).toBe(0);
+    expect(leastCommonMultipleArray([1, 0])).toBe(0);
+    expect(leastCommonMultipleArray([0, 1])).toBe(0);
+    expect(leastCommonMultipleArray([4, 6])).toBe(12);
+    expect(leastCommonMultipleArray([6, 21])).toBe(42);
+    expect(leastCommonMultipleArray([7, 2])).toBe(14);
+    expect(leastCommonMultipleArray([3, 5])).toBe(15);
+    expect(leastCommonMultipleArray([7, 3])).toBe(21);
+    expect(leastCommonMultipleArray([1000000, 2])).toBe(1000000);
+    expect(leastCommonMultipleArray([-9, -18])).toBe(18);
+    expect(leastCommonMultipleArray([-7, -9])).toBe(63);
+    expect(leastCommonMultipleArray([-7, 9])).toBe(63);
+    expect(leastCommonMultipleArray([2, 3, 5])).toBe(30);
+    expect(leastCommonMultipleArray([2, 4, 5])).toBe(20);
+    expect(leastCommonMultipleArray([2, 4, 6, 8])).toBe(24);
+    expect(leastCommonMultipleArray([2, 4, 6, 7, 8])).toBe(168);
+    expect(leastCommonMultipleArray([2, 3, 5, 7, 11, 13, 17, 19])).toBe(9699690);
+  });
+});

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

@@ -0,0 +1,32 @@
+import euclideanAlgorithm from '../euclidean-algorithm/euclideanAlgorithm';
+
+/**
+ * Function to find the least common multiple of an array of numbers.
+ * @param {Array<number>} nums Array of numbers.
+ * @return {number}
+ * @throws {Error("Array is empty")} - Thrown when the input array is empty.
+ */
+
+export default function leastCommonMultipleArray(nums) {
+  // Remove duplicates from array
+  const uniqueNums = [...new Set(nums)];
+  // Checks if array is empty then throw error
+  if (uniqueNums.length === 0) {
+    throw new Error('Array is empty');
+  }
+  // Checks if array contains 0 then return 0 as LCM
+  for (let i = 0; i < uniqueNums.length; i += 1) {
+    if (uniqueNums[i] === 0) {
+      return 0;
+    }
+  }
+  // Initialize LCM with first element of array
+  let lcm = Math.abs(uniqueNums[0]);
+  // Iterate over the array and find LCM of each element
+  for (let i = 1; i < uniqueNums.length; i += 1) {
+    const currentGCD = euclideanAlgorithm(lcm, uniqueNums[i]);
+    lcm = Math.abs(lcm * uniqueNums[i]) / currentGCD;
+  }
+  // Return LCM
+  return lcm;
+}