add solution for leetcode problem 1423 in Kotlin

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
+ }
+}