Update 0189-rotate-array.js

File(s) Modified: 0189-rotate-array.js
Language(s) Used: javascript
Submission URL: https://leetcode.com/problems/rotate-array/submissions/1069667036/
Solution follows the same algorithm shown on the channel (https://www.youtube.com/c/neetcode).

javascript/0189-rotate-array.js

@@ -24,3 +24,41 @@ var reversePortionOfArray = function(nums,start,end) {
  end--;
  } 
 }
+
+
+/**
+ * Two Pointers
+ * https://leetcode.com/problems/rotate-array/
+ * 
+ * Time O(n) | Space O(1)
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {void} Do not return anything, modify nums in-place instead.
+ */
+var rotate = function(nums, k) {
+
+ k = k % nums.length;
+
+ let l = 0;
+ let r = nums.length - 1;
+
+ while (l < r) {
+ [nums[l], nums[r]] = [nums[r], nums[l]];
+ l += 1;
+ r -= 1;
+ }
+ l = 0, 
+ r = k - 1;
+ while (l < r) {
+ [nums[l], nums[r]] = [nums[r], nums[l]];
+ l += 1;
+ r -= 1;
+ }
+ l = k;
+ r = nums.length - 1;
+ while (l < r) {
+ [nums[l], nums[r]] = [nums[r], nums[l]];
+ l += 1;
+ r -= 1;
+ }
+};