Fixed error in Palindrome.java and gave semantic names to functions (TheAlgorithms#3643)

TaranjeetSinghKalsi · Debasish Biswas · web-flow · commit bd267bb7d85d · 2022-10-28T00:17:16.000+05:30
* fixed error and changed functions names

fixed error at line 57 and gave semantic names to functions with comments

* renamed functions

renamed functions to match with original functions' names in the file

* Updated TestCases

Updated TestCases and changed a function name

* Removed main() and changed function name

Removed main() and changed the function name from isPalindromeStringBuilder to isPalindrome

* fixed typo

Co-authored-by: Debasish Biswas &lt;debasishbsws.abc@gmail.com&gt;
diff --git a/src/main/java/com/thealgorithms/strings/Palindrome.java b/src/main/java/com/thealgorithms/strings/Palindrome.java
@@ -6,26 +6,7 @@
 class Palindrome {
 
     /**
-     * Driver Code
-     */
-    public static void main(String[] args) {
-        String[] palindromes = { null, "", "aba", "123321" };
-        for (String s : palindromes) {
-            assert isPalindrome(s) &&
-            isPalindromeRecursion(s) &&
-            isPalindrome1(s);
-        }
-
-        String[] notPalindromes = { "abb", "abc", "abc123" };
-        for (String s : notPalindromes) {
-            assert !isPalindrome(s) &&
-            !isPalindromeRecursion(s) &&
-            !isPalindrome1(s);
-        }
-    }
-
-    /**
-     * Check if a string is palindrome string or not
+     * Check if a string is palindrome string or not using String Builder
      *
      * @param s a string to check
      * @return {@code true} if given string is palindrome, otherwise
@@ -54,17 +35,17 @@ public static boolean isPalindromeRecursion(String s) {
             return false;
         }
 
-        return isPalindrome(s.substring(1, s.length() - 1));
+        return isPalindromeRecursion(s.substring(1, s.length() - 1));
     }
 
     /**
-     * Check if a string is palindrome string or not another way
+     * Check if a string is palindrome string or not using two pointer technique
      *
      * @param s a string to check
      * @return {@code true} if given string is palindrome, otherwise
      * {@code false}
      */
-    public static boolean isPalindrome1(String s) {
+    public static boolean isPalindromeTwoPointer(String s) {
         if (s == null || s.length() <= 1) {
             return true;
         }
diff --git a/src/test/java/com/thealgorithms/strings/PalindromeTest.java b/src/test/java/com/thealgorithms/strings/PalindromeTest.java
@@ -7,13 +7,20 @@ public class PalindromeTest {
 
     @Test
     public void palindrome() {
-        String input1 = "kayak";
-        String input2 = "kayaks";
-        Assertions.assertTrue(Palindrome.isPalindrome(input1));
-        Assertions.assertFalse(Palindrome.isPalindrome(input2));
-        Assertions.assertTrue(Palindrome.isPalindromeRecursion(input1));
-        Assertions.assertFalse(Palindrome.isPalindromeRecursion(input2));
-        Assertions.assertTrue(Palindrome.isPalindrome1(input1));
-        Assertions.assertFalse(Palindrome.isPalindrome1(input2));
+
+        String[] palindromes = { null, "", "aba", "123321", "kayak" };
+        for (String s : palindromes) {
+            Assertions.assertTrue(Palindrome.isPalindrome(s) &&
+            Palindrome.isPalindromeRecursion(s) &&
+            Palindrome.isPalindromeTwoPointer(s));
+        }
+
+        String[] notPalindromes = { "abb", "abc", "abc123", "kayaks" };
+        for (String s : notPalindromes) {
+            Assertions.assertFalse(Palindrome.isPalindrome(s) ||
+            Palindrome.isPalindromeRecursion(s) ||
+            Palindrome.isPalindromeTwoPointer(s));
+        }
+        
     }
 }
