add MainExercises.java and BonusExercise.java

src/main/java/BonusExercises.java

@@ -1,3 +1,6 @@
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Matcher;
@@ -20,11 +23,51 @@ public class BonusExercises {
             - Each segment (between dots) must follow same hyphen rules
      */
     public boolean validateEmail(String email) {
-        String regex = ""; // todo
-        Pattern pattern = Pattern.compile(regex);
-        Matcher matcher = pattern.matcher(email);
 
-        return matcher.matches();
+
+        if (email.contains(" "))
+            return false;
+
+        int count = 0;
+        int index = 0;
+
+        // rule 1:
+        for (int i = 0; i < email.length() -1; i++)  {
+
+            if (email.charAt(i) == '@') {
+                count++;
+                index = i;
+            }
+        }
+
+        if (count != 1)
+            return false;
+
+
+
+
+        // rule 2:
+        String localPart = email.substring(0,index);
+        String domainPart = email.substring(index + 1);
+
+
+        if (localPart.isEmpty() || domainPart.isEmpty())
+            return false;
+
+        if (localPart.startsWith(".") || localPart.endsWith(".") ||
+                domainPart.startsWith(".") || domainPart.endsWith("."))
+            return false;
+
+        if (localPart.contains(".."))
+            return false;
+
+        if (domainPart.contains("_"))
+            return false;
+
+
+        
+
+        return true;
     }
 
     /*
@@ -39,7 +82,7 @@ public class BonusExercises {
         If no match for a date is found in the string, return null.
     */
     public String findDate(String string) {
-        // todo
+
         return null;
     }
 
@@ -54,8 +97,42 @@ public class BonusExercises {
         - has no white-space in it
      */
     public int findValidPasswords(String string) {
-        // todo
-        return -1;
+
+        if (string.length() < 8)
+            return 0;
+
+        int validPassWords = 0;
+
+        List<String> subStrings = List.of(string.split("\\s+"));
+
+
+        for (String newPart : subStrings) {
+
+            //at least 8 characters
+            if (newPart.length() < 8)
+                continue;
+
+
+            // at least one uppercase letter
+            if (!newPart.matches(".*[A-Z].*"))
+                continue;
+
+            // and at least a lowercase
+            if (!newPart.matches(".*[a-z].*"))
+                continue;
+
+            // at least one number
+            if (!newPart.matches(".*\\d.*"))
+                continue;
+
+            // at least one spacial character
+            if (!newPart.matches(".*[!@#$%^&*].*"))
+                continue;
+
+            validPassWords++;
+        }
+
+            return validPassWords;
     }
 
     /*
@@ -66,11 +143,39 @@ public class BonusExercises {
      */
     public List<String> findPalindromes(String string) {
         List<String> list = new ArrayList<>();
-        // todo
+
+        Pattern words = Pattern.compile("[a-zA-Z]+");
+        Matcher matcher = words.matcher(string);
+
+        while (matcher.find()) {
+
+            String word = matcher.group();
+
+            if (word.length() < 2)
+                continue;
+
+            String reversed = new StringBuilder(word).reverse().toString();
+
+            if (reversed.equalsIgnoreCase(word))
+                list.add(word);
+
+        }
+
         return list;
     }
 
     public static void main(String[] args) {
         // you can test your code here
+
+        BonusExercises kir = new BonusExercises();
+
+        System.out.println(kir.findValidPasswords("""
+                [09:15] Dev1: Just changed my password to CodeMaster@2025. \s
+                [09:17] Dev2: Haha, mine's still qwerty123, no special chars. \s
+                [09:19] Dev3: I use GitHubSuper#1 but need a better one. \s
+                [09:21] Dev4: AdminPass42! is good, right? \s
+                [09:23] Dev5: No, too simple. I switched to UltraSecure$99 last week. \s
+                [09:25] Dev6: Wait, are we sharing passwords here? \uD83D\uDE02 \s
+                """));
     }
 }