pom.xml

@@ -21,6 +21,24 @@
             <version>5.11.4</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>RELEASE</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

src/main/java/BonusExercises.java

@@ -20,7 +20,7 @@ public class BonusExercises {
             - Each segment (between dots) must follow same hyphen rules
      */
     public boolean validateEmail(String email) {
-        String regex = ""; // todo
+        String regex = "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$"; // todo
         Pattern pattern = Pattern.compile(regex);
         Matcher matcher = pattern.matcher(email);
 
@@ -39,7 +39,14 @@ public class BonusExercises {
         If no match for a date is found in the string, return null.
     */
     public String findDate(String string) {
-        // todo
+        String regex = "\\b(\\d{2}/\\d{2}/\\d{4}|\\d{4}-\\d{2}-\\d{2}|\\d{4}/\\d{2}/\\d{2})\\b";
+
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(string);
+
+        if (matcher.find()) {
+            return matcher.group();
+        }
         return null;
     }
 
@@ -54,8 +61,17 @@ public class BonusExercises {
         - has no white-space in it
      */
     public int findValidPasswords(String string) {
-        // todo
+        String regex = "(?<!\\S)(?=\\S*[A-Z])(?=\\S*[a-z])(?=\\S*\\d)(?=\\S*[!@#$%^&*])[^\\s]{8,}(?!\\S)";
-        return -1;
+
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(string);
+
+        int count = 0;
+        while (matcher.find()) {
+            count++;
+        }
+
+        return count;
     }
 
     /*

src/main/java/MainExercises.java

@@ -1,3 +1,6 @@
+import java.util.ArrayList;
+import java.util.List;
+
 public class MainExercises
 {
     /*
@@ -20,9 +23,27 @@ public class MainExercises
  */
     public char[][] generateTriangle(int n) {
 
-        // todo
+        if (n <= 0) {
-        return null;
+            return new char[0][0];
-
+        }
+        char[][] result = new char[n][];
+        for (int i = 0; i < n; i++) {
+            result[i] = new char[i + 1];
+            if (i == 0) {
+                result[i][0] = '*';
+            } else if (i == n - 1) {
+                for (int j = 0; j <= i; j++) {
+                    result[i][j] = '*';
+                }
+            } else {
+                result[i][0] = '*';
+                result[i][i] = '*';
+                for (int j = 1; j < i; j++) {
+                    result[i][j] = ' ';
+                }
+            }
+        }
+        return result;
     }
 
 
@@ -58,8 +79,49 @@ public class MainExercises
            - Number of columns: matrix[0].length (if rectangular)
    */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
+        if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
-        return null;
+            return new int[0];
+        }
+
+        int rows = matrix.length;
+        int cols = matrix[0].length;
+        int[] result = new int[rows * cols];
+        int index = 0;
+
+        int top = 0;
+        int bottom = rows - 1;
+        int left = 0;
+        int right = cols - 1;
+
+
+        while (top <= bottom && left <= right) {
+
+            for (int j = left; j <= right; j++) {
+                result[index++] = matrix[top][j];
+            }
+            top++;
+
+            for (int i = top; i <= bottom; i++) {
+                result[index++] = matrix[i][right];
+            }
+            right--;
+
+            if (top <= bottom) {
+                for (int j = right; j >= left; j--) {
+                    result[index++] = matrix[bottom][j];
+                }
+                bottom--;
+            }
+
+            if (left <= right) {
+                for (int i = bottom; i >= top; i--) {
+                    result[index++] = matrix[i][left];
+                }
+                left++;
+            }
+        }
+
+        return result;
     }
 
     /*
@@ -91,8 +153,32 @@ public class MainExercises
     */
 
     public int[][] intPartitions(int n) {
-        // todo
+        if (n <= 0) return new int[0][0];
-        return null;
+
+        List<int[]> resultList = new ArrayList<>();
+        findPartitions(n, n, new ArrayList<>(), resultList);
+
+        int[][] resultArray = new int[resultList.size()][];
+        for (int i = 0; i < resultList.size(); i++) {
+            resultArray[i] = resultList.get(i);
+        }
+        return resultArray;
+    }
+    private void findPartitions(int n, int max, List<Integer> current, List<int[]> resultList) {
+        if (n == 0) {
+            int[] partition = new int[current.size()];
+            for (int i = 0; i < current.size(); i++) {
+                partition[i] = current.get(i);
+            }
+            resultList.add(partition);
+            return;
+        }
+
+        for (int i = Math.min(max, n); i >= 1; i--) {
+            current.add(i);
+            findPartitions(n - i, i, current, resultList);
+            current.removeLast();
+        }
     }