Merge Sort in JavaScript

JavaScript/README.md

@@ -10,6 +10,7 @@
 # Codes in the Javascript language
 
 ## Algorithms
+
 - [Russian Peasant Algorithm](Algorithms/RussianPeasant.js)
 - [Z Algorithm](Algorithms/ZAlgorithm.js)
 - [Boyer Moore's Majority Vote Algorithm](Algorithms/BoyerMooreAlgorithm.js)
@@ -36,6 +37,7 @@
 - [Insertion Sort](./sort/insertion_sort.js)
 - [Sleep Sort](./sort/sleepSort.js)
 - [Quick Sort](./sort/quicksort.js)
+- [Merge Sort](./sort/MergeSort.js)
 
 ## Machine Learning
 

JavaScript/sort/MergeSort.js

@@ -0,0 +1,51 @@
+/**
+ *
+ * Merge sort uses the concept of divide-and-conquer to sort the given list of elements.
+ * It breaks down the problem into smaller subproblems until they become simple enough to solve directly.
+ * 
+ * Time Complexity: O(nlogn)
+ * 
+ * Space Complexity: O(n) 
+ */
+function merge(left, right) {
+  let arr = [];
+  // Break out of loop if any one of the array gets empty
+  while (left.length && right.length) {
+    // Pick the smaller among the smallest element of left and right sub arrays
+    if (left[0] < right[0]) {
+      arr.push(left.shift());
+    } else {
+      arr.push(right.shift());
+    }
+  }
+
+  // Concatenating the leftover elements
+  // (in case we didn't go through the entire left or right array)
+  return [...arr, ...left, ...right];
+}
+
+function mergeSort(array) {
+  const half = array.length / 2;
+
+  // Base case or terminating case
+  if (array.length < 2) {
+    return array;
+  }
+
+  const left = array.splice(0, half);
+  return merge(mergeSort(left), mergeSort(array));
+}
+
+var array = prompt("Enter Numbers to Sort (Comma Separated) : ").split(",");
+// You Can also give static input if prompt() not works for you. like this :
+// array = [4, 8, 7, 2, 11, 1, 3];
+
+console.log(mergeSort(array));
+
+/*
+ * Sample Input:
+ * 96,56,53,85,115,20
+ *
+ * Sample Output:
+ * 20,53,56,85,96,115
+ */