add Kotlin solution for 978. Longest Turbulent Subarray

Author: technophilist

kotlin/0978-longest-turbulent-subarray.kt

@@ -0,0 +1,30 @@
+class Solution {
+    fun maxTurbulenceSize(arr: IntArray): Int {
+        if (arr.size == 1) return 1
+        var previousEqualitySymbol = ' '
+        var currentSubArraySize = 1
+        var maxSubArraySize = 1
+        for (i in 1..arr.lastIndex) {
+            if (arr[i - 1] > arr[i] && previousEqualitySymbol != '>') {
+                currentSubArraySize++
+                maxSubArraySize = maxOf(maxSubArraySize, currentSubArraySize)
+                previousEqualitySymbol = '>'
+                continue
+            }
+            if (arr[i - 1] < arr[i] && previousEqualitySymbol != '<') {
+                currentSubArraySize++
+                maxSubArraySize = maxOf(maxSubArraySize, currentSubArraySize)
+                previousEqualitySymbol = '<'
+                continue
+            }
+            currentSubArraySize = if (arr[i - 1] == arr[i]) 1 else 2
+            maxSubArraySize = maxOf(maxSubArraySize, currentSubArraySize)
+            previousEqualitySymbol = when {
+                arr[i - 1] < arr[i] -> '<'
+                arr[i - 1] > arr[i] -> '>'
+                else -> ' '
+            }
+        }
+        return maxSubArraySize
+    }
+}