Complete

src/main/java/BonusExercises.java

@@ -39,7 +39,21 @@ public class BonusExercises {
         If no match for a date is found in the string, return null.
     */
     public String findDate(String string) {
-        // todo
+        String regex1 = "\\d{4}[-/](0[1-9]|1[0-2])[-/](0[1-9]|[12]\\d|3[01])";
+        String regex2 = "(0[1-9]|[12]\\d|3[01])/(0[1-9]|1[0-2])/\\d{4}";
+
+        Pattern pattern1 = Pattern.compile(regex1);
+        Pattern pattern2 = Pattern.compile(regex2);
+        Matcher matcher1 = pattern1.matcher(string);
+        Matcher matcher2 = pattern2.matcher(string);
+
+        if (matcher1.find()) {
+            return matcher1.group();
+        }
+
+        if (matcher2.find()) {
+            return matcher2.group();
+        }
         return null;
     }
 
@@ -54,8 +68,42 @@ public class BonusExercises {
         - has no white-space in it
      */
     public int findValidPasswords(String string) {
-        // todo
+        int count = 0;
-        return -1;
+        String[] parts = string.split(" ");
+
+        for (String p : parts) {
+            if (p.length() < 8) {
+                continue;
+            }
+            boolean hasUpper = false;
+            boolean hasLower = false;
+            boolean hasNumber = false;
+            boolean hasSpecial = false;
+            boolean hasSpace = false;
+
+            for (int i = 0; i < p.length(); i++) {
+                char c = p.charAt(i);
+                if (Character.isUpperCase(c)) {
+                    hasUpper = true;
+                }
+                else if (Character.isLowerCase(c)) {
+                    hasLower = true;
+                }
+                else if (Character.isDigit(c)) {
+                    hasNumber = true;
+                }
+                else if (Character.isWhitespace(c)) {
+                    hasSpace = true;
+                }
+                else {
+                    hasSpecial = true;
+                }
+            }
+            if (!hasSpace && hasUpper && hasLower && hasNumber && hasSpecial) {
+                count++;
+            }
+        }
+        return count;
     }
 
     /*
@@ -66,7 +114,18 @@ public class BonusExercises {
      */
     public List<String> findPalindromes(String string) {
         List<String> list = new ArrayList<>();
-        // todo
+        String[] words = string.split(" ");
+
+        for (String w : words) {
+            String clean = w.replaceAll("[^A-Za-z]", "");
+            if (clean.length() >= 3) {
+                String lower = clean.toLowerCase() ;
+                String reversed = new StringBuilder(lower).reverse().toString();
+                if (lower.equals(reversed)) {
+                    list.add(clean);
+                }
+            }
+        }
         return list;
     }
 

src/main/java/MainExercises.java

@@ -1,98 +1,91 @@
+import java.util.ArrayList;
+import java.util.List;
+
 public class MainExercises
 {
-    /*
-    you should create a triangle with "*" and return a two-dimensional array of characters based on that
-    the triangle's area is empty, which means some characters should be " "
-
-    example 1, input = 3:
-    *
-    **
-    ***
-
-    example 2, input = 5:
-    *
-    **
-    * *
-    *  *
-    *****
-
-    the output has to be a two-dimensional array of characters, so don't just print the triangle!
- */
     public char[][] generateTriangle(int n) {
+        if (n == 0) {
+            return new char[0][0];
+        }
+        char[][] triangle = new char[n][];
 
-        // todo
+        for (int i = 0; i < n; i++) {
-        return null;
+            triangle[i] = new char[i + 1];
+            for (int j = 0; j <= i; j++) {
+                if (i == 0 || i == n - 1) {
+                    triangle[i][j] = '*';
+                }
+                else {
+                    if (j == 0 || j == i) {
+                        triangle[i][j] = '*';
+                    }
+                    else {
+                        triangle[i][j] = ' ';
+                    }
+                }
+            }
+        }
+        return triangle;
 
     }
 
 
-
-    /*
-       SPIRAL TRAVERSAL OF A RECTANGULAR MATRIX
-
-       Given a rectangular matrix (2D array) of integers, this method traverses
-       it in a spiral order (clockwise from outside to inside) and returns
-       the elements as a 1D array.
-
-       EXAMPLE:
-       Input matrix:
-           1  2  3
-           4  5  6
-           7  8  9
-
-       Spiral order: start at top-left (1), go right →, then down ↓,
-       then left ←, then up ↑, then repeat inward.
-
-       Result: {1, 2, 3, 6, 9, 8, 7, 4, 5}
-
-       so you should walk in that matrix in a curl and then add the numbers in order you've seen them in a 1D array
-
-       RECTANGULAR MATRIX ASSUMPTION:
-       This method assumes the input matrix is RECTANGULAR (all rows have
-       the same number of columns). In Java, we can verify this because
-       2D arrays might be jagged (rows of different lengths).
-
-       IMPORTANT: In Java, we do NOT need to pass rows and cols!
-       The 2D array 'matrix' knows its own dimensions:
-           - Number of rows:    matrix.length
-           - Number of columns: matrix[0].length (if rectangular)
-   */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
+        int top = 0;
-        return null;
+        int bottom = matrix.length - 1;
+        int left = 0;
+        int right = matrix[0].length - 1;
+        int[] result = new int[matrix.length * matrix[0].length];
+        int index = 0;
+        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;
     }
-
-    /*
-        integer partitioning is a combinatorics problem in discreet maths
-        the problem is to generate sum numbers which their summation is the input number
-
-        e.g. 1 -> all partitions of integer 3 are:
-        3
-        2, 1
-        1, 1, 1
-
-        e.g. 2 -> for number 4 goes as:
-        4
-        3, 1
-        2, 2
-        2, 1, 1
-        1, 1, 1, 1
-
-        Note: As you can see in the examples, we want to generate distinct partitions,
-        which means 1,2 and 2,1 are not different — they count as the same combination.
-
-        You should generate all partitions of the input number.
-
-        Hint: You can determine the size and order of the arrays by finding the pattern
-        of partitions and their count. Trust me, this one's fun and easy :)
-
-        If you're familiar with Lists and ArrayLists, you can also edit the method's
-        body to use them instead of arrays.
-    */
 
     public int[][] intPartitions(int n) {
-        // todo
+        List<List<Integer>> temp = new ArrayList<>();
-        return null;
+        generate(n, n, new ArrayList<>(), temp);
+
+        int[][] output = new int[temp.size()][];
+        for (int i = 0; i < temp.size(); i++) {
+            List<Integer> l = temp.get(i);
+            output[i] = l.stream().mapToInt(Integer::intValue).toArray();
+        }
+
+        return output;
+    }
+
+
+    private void generate(int n, int max, List<Integer> current, List<List<Integer>> result) {
+        if (n == 0) {
+            result.add(new ArrayList<>(current));
+            return;
+        }
+        for (int i = Math.min(n, max); i >= 1; i--) {
+            current.add(i);
+            generate(n - i, i, current, result);
+            current.remove(current.size() - 1);
+        }
     }