Create 2108-find-first-palindromic-string-in-the-array.kt

Author: a93a

kotlin/2108-find-first-palindromic-string-in-the-array.kt

@@ -0,0 +1,52 @@
+// For every word, check that its reverse equals it 
+class Solution {
+    fun firstPalindrome(words: Array<String>): String {
+        words.forEach { word ->
+            if (word == word.reversed())
+                return word
+        }
+
+        return ""
+    }
+}
+
+// For every word, check that its reverse equals it but using two pointers
+class Solution {
+    fun firstPalindrome(words: Array<String>): String {
+        words.forEach { word ->
+            var l = 0
+            var r = word.lastIndex
+            while (word[l] == word[r]) {
+                if (l >= r) return word
+                l++
+                r--
+            }
+        }
+
+        return ""
+    }
+}
+
+// For every word, check that its reverse equals it but using two pointers with slightly different logic
+class Solution {
+    fun firstPalindrome(words: Array<String>): String {
+        words.forEach { w ->
+            var l = 0
+            var r = w.lastIndex
+            while (l < r && w[l] == w[r]) {
+                l++
+                r--
+            }
+            
+            if (w.length % 2 == 1 && l == r || l == r + 1) return w
+        }
+
+        return ""
+    }
+}
+
+// Use Kotlins power to condense the solution
+class Solution {
+    fun firstPalindrome(words: Array<String>) = words
+        .firstOrNull { it == it.reversed() } ?: ""
+}