Added a function to calculate GCD of Multiple numbers

README.md

@@ -1,6 +1,6 @@
 # algorithms-js [![Build Status](https://travis-ci.org/manrajgrover/algorithms-js.svg?branch=master)](https://travis-ci.org/manrajgrover/algorithms-js) [![Build status](https://ci.appveyor.com/api/projects/status/6l0vybrb4y0c7eh8?svg=true)](https://ci.appveyor.com/project/manrajgrover/algorithms-js) [![npm](https://img.shields.io/npm/v/algorithms-js.svg?maxAge=2592000?style=flat-square)](https://www.npmjs.com/package/algorithms-js) [![npm](https://img.shields.io/npm/dt/algorithms-js.svg?maxAge=2592000?style=flat-square)](https://www.npmjs.com/package/algorithms-js) ![awesome](https://img.shields.io/badge/awesome-yes-green.svg)
-> Consumable Data Structures and Algorithms library in JavaScript
 
+> Consumable Data Structures and Algorithms library in JavaScript
 
 ## Note
 
@@ -27,9 +27,11 @@ Or use `jsdeliver`:
 ```
 
 ## Usage
+
 Library contains both algorithms as well as data structures:
 
 ### Data Structures
+
 Currently, library supports following data structures:
 
 - [Doubly Linked List](https://github.com/manrajgrover/algorithms-js/blob/master/src/data-structures/doubly_linked_list.js)
@@ -42,9 +44,11 @@ Currently, library supports following data structures:
 - [Trie](https://github.com/manrajgrover/algorithms-js/blob/master/src/data-structures/trie.js)
 
 ### Algorithms
+
 Currently library supports following algorithms:
 
 #### Search
+
 Various Searching algorithms:
 
 - [Binary Search](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/search/binary_search.js)
@@ -57,6 +61,7 @@ Various Searching algorithms:
 - [Ternary Search](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/search/ternary_search.js)
 
 #### Sort
+
 Various Sorting algorithms:
 
 - [Bubble Sort](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/sort/bubble_sort.js)
@@ -68,19 +73,23 @@ Various Sorting algorithms:
 - [Selection Sort](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/sort/selection_sort.js)
 
 #### Math
+
 Various Math algorithms:
 
 - [Extended Euclidean](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/math/extended_euclidean.js)
 - [Fast Exponentiation](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/math/fast_exp.js)
 - [GCD](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/math/gcd.js)
+- [GCD of Multiple Numbers](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/math/gcd_multiple_numbers.js)
 - [LCM](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/math/lcm.js)
 
 #### String
+
 Various String algorithms:
 
 - [Levenshtein Distance](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/string/levenshtein_distance.js)
 
 #### Geometry
+
 Various Geometry algorithms:
 
 - [Tangent between circles](https://github.com/manrajgrover/algorithms-js/blob/master/src/algorithms/geometry/tangent_between_circles.js)
@@ -128,6 +137,7 @@ $ npm run build-dev
 ```
 
 ## Get in touch
+
 Say hi on [twitter](https://twitter.com/manrajsgrover)
 
 ## License

src/algorithms/math/gcd_multiple_numbers.js

@@ -0,0 +1,44 @@
+/**
+ * Calculates GCD of multiple numbers
+ * @param  {Number, Number... Number}
+ * @return {Number}   HCF or GCD of provided numbers
+ *
+ * References: https://www.geeksforgeeks.org/python-program-for-gcd-of-more-than-two-or-array-numbers/
+ */
+function gcd_multiple_numbers() {
+  if (arguments.length < 2) {
+    console.error(
+      `Function gcd_multiple_numbers requires atleast 2 arguments, but only ${arguments.length} provided.`
+    );
+    return;
+  }
+  const GCD = (a, b) => {
+    a = Math.abs(a);
+    b = Math.abs(b);
+
+    if (a === 0 || b === 0) {
+      return 0;
+    }
+
+    if (a === b) {
+      return a;
+    }
+
+    if (a > b) {
+      return GCD(a - b, b);
+    }
+
+    return GCD(a, b - a);
+  };
+
+  num1 = arguments[0];
+  num2 = arguments[1];
+  let gcd = GCD(num1, num2);
+  for (let i = 2; i < arguments.length; i++) {
+    gcd = GCD(gcd, arguments[i]);
+  }
+
+  return gcd;
+}
+
+module.exports = gcd_multiple_numbers;

src/algorithms/math/index.js

@@ -1,13 +1,15 @@
-const extendedEuclidean = require('./extended_euclidean');
-const gcd = require('./gcd');
-const fastexp = require('./fast_exp');
-const lcm = require('./lcm');
-const modularInverse = require('./modular_inverse');
+const extendedEuclidean = require("./extended_euclidean");
+const gcd = require("./gcd");
+const gcd_multiple_numbers = require("./gcd_multiple_numbers");
+const fastexp = require("./fast_exp");
+const lcm = require("./lcm");
+const modularInverse = require("./modular_inverse");
 
 module.exports = {
   extendedEuclidean,
   gcd,
+  gcd_multiple_numbers,
   fastexp,
   lcm,
-  modularInverse
+  modularInverse,
 };