feat: add LCM function (#185)

* Add LCM function

* Add index and package

* Fix lint issue

* Revert package.json changes

package.json

@@ -101,4 +101,4 @@
       "kentcdodds/ava"
     ]
   }
-}
+}

src/index.js

@@ -66,6 +66,7 @@ import generatePassword from './generate-password'
 import tail from './tail'
 import makeObjectIterable from './makeObjectIterable'
 import fibonacciSum from './fibonacciSum'
+import lcm from './lcm'
 
 export {
   reverseArrayInPlace,
@@ -136,4 +137,5 @@ export {
   tail,
   makeObjectIterable,
   fibonacciSum,
+  lcm,
 }

src/lcm.js

@@ -0,0 +1,23 @@
+export default lcm
+
+/**
+ * Original source: https://stackoverflow.com/a/38407734
+ *
+ * This method returns least common multiple of two integers
+ *
+ * @param {Number} a - first integer
+ * @param {Number} b - second integer
+ * @return {Number} - least common multiple
+ */
+
+function gcd(a, b) {
+  if (b === 0) {
+    return a
+  } else {
+    return gcd(b, a % b)
+  }
+}
+
+function lcm(a, b) {
+  return a * b / gcd(a, b)
+}

test/lcm.test.js

@@ -0,0 +1,18 @@
+import test from 'ava'
+import {lcm} from '../src'
+
+test('Get lcm of two unequal integers', t => {
+  const a = 8
+  const b = 12
+  const expected = 24
+  const actual = lcm(a, b)
+  t.deepEqual(actual, expected)
+})
+
+test('Get lcm of equal integers', t => {
+  const a = 11
+  const b = 11
+  const expected = 11
+  const actual = lcm(a, b)
+  t.deepEqual(actual, expected)
+})