Merge pull request neetcode-gh#2544 from aadil42/patch-45

Create 0912-sort-an-array.js

Author: aakhtar3

javascript/0912-sort-an-array.js

@@ -0,0 +1,53 @@
+/**
+ * https://leetcode.com/problems/sort-an-array/
+ * Merge Sort
+ * Time O(n*log(n)) | Space O(n)
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+const sortArray = function(nums) {
+    return mergeSort(0, nums.length  - 1, nums);
+};  
+
+const mergeSort = (left, right, nums) => {
+
+    if(left === right) return nums;
+    
+    const mid = Math.floor((left+right)/2);
+    mergeSort(left, mid, nums);
+    mergeSort(mid+1, right, nums);
+    return merge(left, right, mid, nums);
+}
+
+const merge = (left, right, mid, nums) => {
+    const arr1 = nums.slice(left, mid+1);
+    const arr2 = nums.slice(mid+1, right + 1);
+    
+    let p1 = 0; 
+    let p2 = 0;
+    let gp = left;
+
+    while(p1 < arr1.length && p2 < arr2.length) {
+        if(arr1[p1] < arr2[p2]) {
+            nums[gp] = arr1[p1];
+            p1++;
+        } else {
+            nums[gp] = arr2[p2];
+            p2++;
+        }
+        gp++;
+    }
+
+    while(p1 < arr1.length) {
+        nums[gp] = arr1[p1];
+        p1++;
+        gp++;
+    }
+
+    while(p2 < arr2.length) {
+        nums[gp] = arr2[p2];
+        p2++;
+        gp++;
+    }
+    return nums;
+}