add 1299 kotlin solution

Author: Zhaoshan-Duan

kotlin/1299-replace-elements-with-greatest-element-on-right-side.kt

@@ -0,0 +1,12 @@
+class Solution {
+    fun replaceElements(arr: IntArray): IntArray {
+        val res = IntArray(arr.size)
+        var max = -1
+
+        arr.reversed().forEachIndexed { i, value ->
+            res[i] = max
+            max = maxOf(max, value)
+        }
+        return res.reversed().toIntArray()
+    }
+}