add solution for leetcode problem 1423 in Kotlin

Author: technophilist

kotlin/1423-maximum-points-you-can-obtain-from-cards.kt

@@ -0,0 +1,23 @@
+class Solution {
+    fun maxScore(cardPoints: IntArray, k: Int): Int {
+        if (cardPoints.size == k) return cardPoints.sum()
+        var l = cardPoints.size - k
+        var r = cardPoints.lastIndex
+
+        var maxScore = 0
+        var currentScore = 0
+        // the sum of the initial sub-array
+        for (i in l..r) {
+            maxScore += cardPoints[i]
+            currentScore += cardPoints[i]
+        }
+
+        while (true) {
+            currentScore -= cardPoints[l++ % cardPoints.size]
+            currentScore += cardPoints[++r % cardPoints.size]
+            maxScore = maxOf(maxScore, currentScore)
+            if (l % cardPoints.size == 0) break
+        }
+        return maxScore
+    }
+}