Simplify CheckVowels (#3172)

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

@@ -19,24 +19,15 @@ public class CheckVowels {
      * @return {@code true} if given string has vowels, otherwise {@code false}
      */
     public static boolean hasVowels(String input) {
-        return countVowels(input) > 0;
-    }
-
-    /**
-     * count the number of vowels
-     *
-     * @param input a string prints the count of vowels
-     */
-    public static int countVowels(String input) {
         if (input == null) {
-            return 0;
+            return false;
         }
-        int cnt = 0;
-        for (char c : input.toLowerCase().toCharArray()) {
-            if (VOWELS.contains(c)) {
-                ++cnt;
+        input = input.toLowerCase();
+        for (int i = 0; i < input.length(); i++) {
+            if (VOWELS.contains(input.charAt(i))) {
+                return true;
             }
         }
-        return cnt;
+        return false;
     }
 }