Update 1299-Replace-Elements-With-Greatest-Element-On-Right-Side.js

javascript/1299-Replace-Elements-With-Greatest-Element-On-Right-Side.js

@@ -1,17 +1,35 @@
 /**
+ * Reverse - Space O(1)
+ * Time O(N) | Space O(N)
+ * https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/
+ * @param {number[]} arr
+ * @return {number[]}
+ */
+var replaceElements = (arr, max = -1, ans = [ -1 ]) => { 
+ arr = arr.reverse(); /* Time O(N) */
+
+ for (let i = 0; (i < (arr.length - 1)); i++) {/* Time O(N) */
+ max = Math.max(max, arr[i]);
+ ans[(i + 1)] = max; /* Space O(N) */
+ }
+
+ return ans.reverse(); /* Time O(N) */
+};
+
+/**
+ * Backward - In-Place
  * Time O(N) | Space O(1)
- * 
+ * https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/
  * @param {number[]} arr
  * @return {number[]}
  */
-function replaceElements(arr) {
- let max = -1;
+var replaceElements = (arr, max = -1) => { 
+ for (let i = (arr.length - 1); (0 <= i); i--) {/* Time O(N) */
+ const num = arr[i];
 
- for (let i = arr.length - 1; i >= 0; i--) {
- const temp = arr[i];
- arr[i] = max;
- max = Math.max(max, temp);
- }
+ arr[i] = max;
+ max = Math.max(max, num);
+ }
 
- return arr;
-};
+  return arr;
+ };