August Day 3

Author: suriyakrishna

src/main/scala/com/leetcode/scala/monthly2020/august/ValidPalindrome.scala

@@ -0,0 +1,50 @@
+package com.leetcode.scala.monthly2020.august
+
+/*
+* Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.
+*
+* Note: For the purpose of this problem, we define empty string as valid palindrome.
+*
+*  */
+
+/*
+* Input: "A man, a plan, a canal: Panama"
+  Output: true
+*
+* Input: "race a car"
+  Output: false
+*
+* Constraints:
+  * s consists only of printable ASCII characters.
+*
+* */
+
+/*
+* Approach: Iterative
+* 1. Iterate through each character and form the string alphaNumeric character.
+* 2. Compare the new string value with reverse value of new string.
+*
+* */
+
+
+object ValidPalindrome {
+  def main(args: Array[String]): Unit = {
+    val s1 = "A man, a plan, a canal: Panama"
+    val s2 = "race a car"
+    val s3 = "0p"
+    val testCases = Array(s1, s2, s3)
+    val expectedResults = Array(true, false, false)
+    val actualResults = testCases.map(isPalindrome)
+    println(s"Results: ${actualResults.mkString(" ")}, ${actualResults.sameElements(expectedResults)}")
+  }
+
+  def isPalindrome(s: String): Boolean = {
+    var string: StringBuilder = new StringBuilder()
+    for (char <- s) {
+      if ((char >= 'a' && char <= 'z') || (char >= 'A' && char <= 'Z') || (char >= '0' && char <= '9')) {
+        string = string.append(char.toLower)
+      }
+    }
+    return string.equals(string.reverse)
+  }
+}