Replace elements with greatest number to the right

33rd exercise - leetcode.com/problems/replace-elements-with-greatest-element-on-right-side/

greatestToTheRight.js

@@ -0,0 +1,22 @@
+/*
+Given an array arr, replace every element in that array with the greatest element among the elements to its right, and replace the last element with -1.
+
+After doing so, return the array.
+
+ 
+
+Example 1:
+
+Input: arr = [17,18,5,4,6,1]
+Output: [18,6,6,6,1,-1]
+*/
+
+//Answer//
+
+/**
+ * @param {number[]} arr
+ * @return {number[]}
+ */
+var replaceElements = function(arr) {
+    return arr.map((x,i)=>i===(arr.length-1)?-1:Math.max(...arr.slice(i+1)))
+};