Merge pull request #19 from alessandron3/master

Added Palindrome algorithm

Author: regan-hoffman

src/main/kotlin/other/Palindrome.kt

@@ -0,0 +1,36 @@
+package other
+
+import java.text.Normalizer
+import java.util.regex.Pattern
+
+/**
+ * A palindrome is a word, number, phrase, or other sequence
+ * of characters which reads the same backward as forward,
+ * such as madam, racecar. There are also numeric palindromes,
+ * particularly date/time stamps using short digits 11/11/11 11:11
+ * and long digits 02/02/2020
+ *
+ * This function
+ * @param text The text to be checked if it is a palindrome
+ * @return return true if the text is a Palindrome
+ */
+fun isPalindrome(text: String): Boolean {
+
+    val normalizedText = text.normalize()
+    for(i in normalizedText.indices)
+        if(normalizedText[i] != normalizedText[normalizedText.length - (i + 1)])
+            return false
+    return true;
+}
+
+
+fun String.normalize(): String {
+    val nfdNormalizedString = Normalizer.normalize(this, Normalizer.Form.NFD)
+    return Pattern
+        .compile("\\p{InCombiningDiacriticalMarks}+")
+        .matcher(nfdNormalizedString)
+        .replaceAll("")
+        .toLowerCase()
+        .replace(" ", "")
+
+}

src/test/kotlin/other/PalindromeTest.kt

@@ -0,0 +1,31 @@
+package other
+
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class PalindromeTest {
+
+    @Test
+    fun testPalindromePortuguesePhrase() {
+        val text = "A mãe te ama"
+        assertTrue(isPalindrome(text))
+    }
+
+    @Test
+    fun testPalindromeEnglishPhrase() {
+        val text = "Mr Owl ate my metal worm"
+        assertTrue(isPalindrome(text))
+    }
+
+    @Test
+    fun testPalindromeName() {
+        val text = "Hannah"
+        assertTrue(isPalindrome(text))
+    }
+
+    @Test
+    fun testPalindromeNumber() {
+        val text = "2002"
+        assertTrue(isPalindrome(text))
+    }
+}