Create 0189-rotate-array.kt

Author: a93a

kotlin/0189-rotate-array.kt

@@ -0,0 +1,17 @@
+class Solution {
+    fun rotate(nums: IntArray, k: Int): Unit {
+
+        fun reverse(from: Int, to: Int) {
+            var f = from
+            var t = to
+            while (f < t) {
+                nums[f] = nums[t].also { nums[t--] = nums[f++] }
+            }
+        }
+
+        val modK = (k % nums.size)
+        reverse(0, nums.lastIndex)
+        reverse(0, modK - 1)
+        reverse(modK, nums.lastIndex)
+    }
+}