feat: valid-palindrome solve

Author: Real-Reason

contains-duplicate/Real-Reason.kt

@@ -1,10 +1,10 @@
 package leetcode_study
 
-class Solution {
+class SolutionContainsDuplicate {
     fun containsDuplicate(nums: IntArray): Boolean {
         val size = nums.size
         val numsToSet = nums.toSet()
 
         return size != numsToSet.size
     }
-}
+}

valid-palindrome/Real-Reason.kt

@@ -0,0 +1,27 @@
+package leetcode_study
+
+class SolutionValidPalindrome {
+    fun isPalindrome(s: String): Boolean {
+        val sToCharArray = s.toCharArray()
+        var startIndex = 0
+        var endIndex = sToCharArray.size - 1
+        while (startIndex < endIndex) {
+            if (!sToCharArray[startIndex].isLetterOrDigit() || sToCharArray[startIndex].isWhitespace()) {
+                startIndex++
+                continue
+            }
+            if (!sToCharArray[endIndex].isLetterOrDigit() || sToCharArray[endIndex].isWhitespace()) {
+                endIndex--
+                continue
+            }
+            if (sToCharArray[startIndex].lowercase() == sToCharArray[endIndex].lowercase()) {
+                startIndex++
+                endIndex--
+            } else {
+                return false
+            }
+        }
+
+        return true
+    }
+}