Merge pull request 'develop' (#1) from develop into main

Reviewed-on: mohammadreza/HW-02-git-and-java-practice-mohammadreza#1

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 +143,29 @@ 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
+        
     }
 }

src/main/java/MainExercises.java

@@ -1,3 +1,6 @@
+import java.util.ArrayList;
+import java.util.List;
+
 public class MainExercises
 {
     /*
@@ -20,8 +23,23 @@ public class MainExercises
  */
     public char[][] generateTriangle(int n) {
 
-        // todo
-        return null;
+        char[][] triangle = new char[n][];
+
+        for (int i = 0 ; i < n ; i++)
+            triangle[i] = new char[i +1];
+
+        for (int i = 0 ; i < n ; i++) {
+
+            for (int j = 0 ; j <= i ; j++) {
+
+                if (i == 0 || i == n - 1 || j == 0 || j == i)
+                    triangle[i][j] = '*';
+                else
+                    triangle[i][j] = ' ';
+            }
+        }
+
+        return triangle;
 
     }
 
@@ -58,10 +76,51 @@ public class MainExercises
            - Number of columns: matrix[0].length (if rectangular)
    */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
-        return null;
+
+        if ((matrix == null) || (matrix.length == 0) || (matrix[0].length == 0)) {
+            return new int[0];
+        }
+
+        int rows = matrix.length;
+        int cols = matrix[0].length;
+        List<Integer> resultList = new ArrayList<>();
+
+        int top = 0, bottom = rows - 1, left = 0, right = cols - 1;
+
+        while (top <= bottom && left <= right) {
+
+            for (int i = left; i <= right; i++) {
+                resultList.add(matrix[top][i]);
+            }
+            top++;
+            for (int i = top; i <= bottom; i++) {
+                resultList.add(matrix[i][right]);
+            }
+            right--;
+
+            if (top <= bottom) {
+                for (int i = right; i >= left; i--) {
+                    resultList.add(matrix[bottom][i]);
+                }
+                bottom--;
+            }
+
+            if (left <= right) {
+                for (int i = bottom; i >= top; i--) {
+                    resultList.add(matrix[i][left]);
+                }
+                left++;
+            }
+        }
+        int[] resultArray = new int[resultList.size()];
+        for (int i = 0; i < resultList.size(); i++) {
+            resultArray[i] = resultList.get(i);
+        }
+
+        return resultArray;
     }
 
+
     /*
         integer partitioning is a combinatorics problem in discreet maths
         the problem is to generate sum numbers which their summation is the input number
@@ -90,13 +149,56 @@ public class MainExercises
         body to use them instead of arrays.
     */
 
+
     public int[][] intPartitions(int n) {
-        // todo
-        return null;
+        if (n <= 0) {
+            return new int[0][0];
+        }
+
+        List<List<Integer>> allPartitions = new ArrayList<>();
+        List<Integer> newPartition = new ArrayList<>();
+
+
+        generatePartitions(n, n, newPartition, allPartitions); // using recursion
+
+
+        int[][] result = new int[allPartitions.size()][];
+
+        // Convert List<List<Integer>> to int[][]
+        for (int i = 0; i < allPartitions.size(); i++) {
+
+            List<Integer> partition = allPartitions.get(i);
+            result[i] = new int[partition.size()];
+
+            for (int j = 0; j < partition.size(); j++) {
+                result[i][j] = partition.get(j);
+            }
+        }
+        return result;
+    }
+
+    private void generatePartitions(int n, int maxVal, List<Integer> newPartition, List<List<Integer>> allPartitions) {
+        // Base case: If n becomes 0, we have found a valid partition
+        if (n == 0) {
+            // Add a copy of the current partition to the list of all partitions
+            allPartitions.add(new ArrayList<>(newPartition));
+            return;
+        }
+
+        for (int i = Math.min(n, maxVal); i >= 1; i--) {
+            // Add the current number 'i' to the partition
+            newPartition.add(i);
+
+            // The new maxVal becomes 'i' because the next number cannot be larger than 'i'
+            generatePartitions(n - i, i, newPartition, allPartitions);
+
+            // Remove the last added number 'i' to explore other possibilities
+            newPartition.removeLast();
+        }
     }
 
 
-    public static void main()
+    static void main()
     {
 
     }