update: added K largest array elements

Author: ashokdey

src/_Problems_/k-largest-in-array/index.js

@@ -0,0 +1,22 @@
+const MaxHeap = require('../../_DataStructures_/Heaps/MaxHeap');
+
+/**
+ * Find the 4 largest elements from an array
+ */
+
+function findKLargest(collection, k) {
+  if (!collection || !Array.isArray(collection)) {
+    throw new Error('Invalid / missing collection');
+  }
+
+  // create a MaxHeap using the collection
+  const mh = new MaxHeap(collection);
+  const result = [];
+
+  for (let i = 0; i < k; i += 1) {
+    result.push(mh.getMax());
+  }
+  return result;
+}
+
+module.exports = findKLargest;