refactor: move reverse method to a dedicated class

Author: “gozhort”

src/main/java/com/thealgorithms/strings/ReverseString.java

@@ -36,4 +36,25 @@ public static String reverse2(String str) {
         }
         return new String(value);
     }
+
+    /**
+     * Reverse version 3 the given string using a StringBuilder.
+     * This method converts the string to a character array,
+     * iterates through it in reverse order, and appends each character
+     * to a StringBuilder.
+     *
+     * @param string The input string to be reversed.
+     * @return The reversed string.
+     */
+    public static String reverse3(String string) {
+        if (string.isEmpty()) {
+            return string;
+        }
+        char[] chars = string.toCharArray();
+        StringBuilder sb = new StringBuilder();
+        for (int i = string.length() - 1; i >= 0; i--) {
+            sb.append(chars[i]);
+        }
+        return sb.toString();
+    }
 }

src/main/java/com/thealgorithms/strings/ReverseStringRecursive.java

@@ -18,25 +18,4 @@ public static String reverse(String str) {
             return reverse(str.substring(1)) + str.charAt(0);
         }
     }
-
-    /**
-     * Reverses the given string using a StringBuilder.
-     * This method converts the string to a character array,
-     * iterates through it in reverse order, and appends each character
-     * to a StringBuilder.
-     *
-     * @param string The input string to be reversed.
-     * @return The reversed string.
-     */
-    public static String reverseUsingStringBuilder(String string) {
-        if (string.isEmpty()) {
-            return string;
-        }
-        char[] chars = string.toCharArray();
-        StringBuilder sb = new StringBuilder();
-        for (int i = string.length() - 1; i >= 0; i--) {
-            sb.append(chars[i]);
-        }
-        return sb.toString();
-    }
 }

src/test/java/com/thealgorithms/strings/ReverseStringRecursiveTest.java

@@ -13,12 +13,4 @@ public class ReverseStringRecursiveTest {
     testReverseString(String input, String expectedOutput) {
         assertEquals(expectedOutput, ReverseStringRecursive.reverse(input));
     }
-
-    @ParameterizedTest
-    @CsvSource({"'Hello World', 'dlroW olleH'", "'helloworld', 'dlrowolleh'", "'123456789', '987654321'", "'', ''", "'A', 'A'", "'!123 ABC xyz!', '!zyx CBA 321!'", "'Abc 123 Xyz', 'zyX 321 cbA'", "'12.34,56;78:90', '09:87;65,43.21'", "'abcdEFGHiJKL', 'LKJiHGFEdcba'",
-        "'MixOf123AndText!', '!txeTdnA321fOxiM'"})
-    public void
-    testReverseUsingStringBuilder(String input, String expectedOutput) {
-        assertEquals(expectedOutput, ReverseStringRecursive.reverseUsingStringBuilder(input));
-    }
 }

src/test/java/com/thealgorithms/strings/ReverseStringTest.java

@@ -25,4 +25,10 @@ public void testReverseString(String input, String expectedOutput) {
     public void testReverseString2(String input, String expectedOutput) {
         assertEquals(expectedOutput, ReverseString.reverse2(input));
     }
+
+    @ParameterizedTest
+    @MethodSource("testCases")
+    public void testReverseString3(String input, String expectedOutput) {
+        assertEquals(expectedOutput, ReverseString.reverse3(input));
+    }
 }