Done!

src/main/java/BonusExercises.java

@@ -20,11 +20,39 @@ public class BonusExercises {
             - Each segment (between dots) must follow same hyphen rules
      */
     public boolean validateEmail(String email) {
-        String regex = ""; // todo
+        String regex = "^[^@\\s]+@[^@\\s]+$"; // todo
         Pattern pattern = Pattern.compile(regex);
         Matcher matcher = pattern.matcher(email);
+        if(matcher.find())
+        {
+            String[] s =email.split("@");
+            String local_part = s[0];
+            String domain = s[1];
+            regex = "(^[.].*$) | (^.*[.]$) | (^(?=.*\\.{2}).*$)";
+            pattern = Pattern.compile(regex);
+            matcher = pattern.matcher(local_part);
+            if(matcher.find())
+                return false;
+            regex = "(^-.*$)|(^.*-$)|(_)";
+            pattern = Pattern.compile(regex);
+            matcher = pattern.matcher(domain);
+            if(matcher.find())
+                return false;
+            regex = "[.][^.]+[.]";
+            pattern = Pattern.compile(regex);
+            matcher = pattern.matcher(domain);
 
-        return matcher.matches();
+            while(matcher.find()) {
+                regex = "(^-.*$)|(^.*-$)|(_)";
+                pattern = Pattern.compile(regex);
+                Matcher matcher1 = pattern.matcher(matcher.group());
+                if(matcher1.find())
+                    return false;
+            }
+            return true;
+
+        }
+        return false;
     }
 
     /*
@@ -39,8 +67,51 @@ public class BonusExercises {
         If no match for a date is found in the string, return null.
     */
     public String findDate(String string) {
-        // todo
+
+        Pattern pattern = Pattern.compile( "(?<american>(?<=\\D)(1[0-2]|0?[1-9])/(3[0-1]|[1-2][0-9]|0?[1-9])/[0-9]{4})"
+                + "|(?<british>(?<=\\D)(3[0-1]|[1-2][0-9]|0?[1-9])/(1[0-2]|0?[1-9])/[0-9]{4})"
+                + "|(?<iso>(?<=\\D)[0-9]{4}-(1[0-2]|0?[1-9])-(3[0-1]|[1-2][0-9]|0?[1-9]))"
+                + "|(?<slash>(?<=\\D)[0-9]{4}/(1[0-2]|0?[1-9])/(3[0-1]|[1-2][0-9]|0?[1-9]))");
+        Matcher matcher = pattern.matcher(string);
+        if(!matcher.find())
             return null;
+        String date = matcher.group();
+        String year ="";
+        String month ="";
+        String day ="";
+        if(matcher.group("american")!=null){
+            String[] s = date.split("/");
+             year = s[2];
+             month = s[0];
+             day = s[1];
+        }
+        else if(matcher.group("british")!=null){
+            String[] s = date.split("/");
+             year = s[2];
+             month = s[1];
+             day = s[0];
+        }
+        else if(matcher.group("iso")!=null){
+            String[] s = date.split("-");
+             year = s[0];
+             month = s[1];
+             day = s[2];
+        }
+        else if(matcher.group("slash")!=null){
+            String[] s = date.split("/");
+             year = s[0];
+             month = s[1];
+             day = s[2];
+        }
+        // is date valid?
+        int Year =Integer.parseInt(year);
+
+        if( (month.matches("0?4|0?6|0?9|11")&&day.matches("31")) ||
+        ((Year%400==0||(Year%100!=0&&Year%4==0))&&month.matches("0?2")&&day.matches("3[0-1]")) ||
+        (month.matches("0?2")&&day.matches("3[0-1]|29")) )
+             return null;
+        return date;
+
     }
 
     /*
@@ -54,9 +125,18 @@ public class BonusExercises {
         - has no white-space in it
      */
     public int findValidPasswords(String string) {
-        // todo
-        return -1;
+        int count = 0;
+        Pattern pattern = Pattern.compile("(?=.*[A-Z])(?=.*[a-z])(?=.*\\d)(?=.*[!@#$%^&*]).{8,}");
+
+        for (String s : string.split("\\s+")) {
+            Matcher matcher = pattern.matcher(s);
+            if (matcher.matches()) {
+                count++;
             }
+        }
+        return count;
+    }
+
 
     /*
         you should return a list of *words* which are palindromic
@@ -66,7 +146,25 @@ public class BonusExercises {
      */
     public List<String> findPalindromes(String string) {
         List<String> list = new ArrayList<>();
-        // todo
+        String[] str = string.split(" ");
+        Pattern pattern = Pattern.compile("[a-zA-Z]{3,}", Pattern.CASE_INSENSITIVE);
+        Matcher matcher ;
+        loop:for (String s:str){
+
+             matcher = pattern.matcher(s);
+             if(matcher.find()){
+                 String temp = matcher.group();
+                for (int i = 0; i <= temp.length()/2-1; i++) {
+                    int dumy = temp.charAt(i)-temp.charAt(temp.length()-i-1);
+                    if(dumy!=0&&dumy!='A'-'a'&&dumy!='a'-'A')
+                        continue loop;
+
+
+                }
+                list.add(matcher.group());
+             }
+
+        }
         return list;
     }
 

src/main/java/MainExercises.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+import java.util.Arrays;
 public class MainExercises
 {
     /*
@@ -19,9 +21,18 @@ public class MainExercises
     the output has to be a two-dimensional array of characters, so don't just print the triangle!
  */
     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 j=0; j<=i; j++){
+                if(i==j||i==n-1||j==0)
+                    triangle[i][j]='*';
+                else
+                    triangle[i][j]=' ';
+            }
+        }
+        return triangle;
 
     }
 
@@ -59,7 +70,63 @@ public class MainExercises
    */
     public int[] spiralTraversal(int[][] matrix) {
         // todo
-        return null;
+        int[] start = {0,1, matrix[0].length-2,matrix.length-2};
+        int[] stop = {matrix[0].length-1, matrix.length-1,0,1};
+        int[] S_T = new int[matrix.length*matrix[0].length];
+        int pointer = 0;
+        int Case =0;
+        int row=0;
+        int column=0;
+        /**
+         *
+         *
+         *
+         start[0]<=stop[0]&&start[1]<=stop[1]&&
+         start[2]>=stop[2]&&start[3]>=stop[3]
+         */
+        while (pointer < matrix.length*matrix[0].length){
+            switch (Case){
+                case 0:
+                    for ( column=start[Case]; column<=stop[Case]; column++){
+                        S_T[pointer++]=matrix[row][column];
+                    }
+                    column--;
+                    start[Case]++;
+                    stop[Case]--;
+                    Case ++;
+                    break;
+                case 1:
+                    for ( row=start[Case]; row<=stop[Case]; row++){
+                        S_T[pointer++]=matrix[row][column];
+                    }
+                    row--;
+                    start[Case]++;
+                    stop[Case]--;
+                    Case ++;
+                    break;
+                case 2:
+                    for ( column=start[Case]; column>=stop[Case]; column--){
+                        S_T[pointer++]=matrix[row][column];
+                    }
+                    column++;
+                    start[Case]--;
+                    stop[Case]++;
+                    Case ++;
+                    break;
+                case 3:
+                    for ( row=start[Case]; row>=stop[Case]; row--){
+                        S_T[pointer++]=matrix[row][column];
+                    }
+                    row++;
+                    start[Case]--;
+                    stop[Case]++;
+                    Case=0;
+                    break;
+
+            }
+
+        }
+        return S_T;
     }
 
     /*
@@ -92,7 +159,32 @@ public class MainExercises
 
     public int[][] intPartitions(int n) {
         // todo
-        return null;
+        if(n==1)
+            return new int[][]{new int[]{1}};
+        ArrayList<int[]> list = new ArrayList<int[]>();
+        list.add(new int[]{n});
+        for (int i = n-1; i >=1 ; i--) {
+            int[][]temp = intPartitions(n-i);
+            int rows = temp.length;
+            for (int j = 0; j < rows; j++) {
+                ArrayList<Integer> merged =new ArrayList<>();
+                merged.add(i);
+                if(temp[j][0]<=i) {
+                    for (int k : temp[j]) {
+                        merged.add( k);
+                    }
+                    int[] d = new int[merged.size()];
+                    for(int z=0;z< merged.size();z++) {
+                        d[z] = merged.get(z);
+                    }
+                    list.add(d);
+
+                }
+            }
+
+        }
+       
+       return (int[][]) list.toArray(new int[list.size()][]);
     }
 
 

src/test/.idea/misc.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_24" project-jdk-name="25" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

src/test/.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/test.iml" filepath="$PROJECT_DIR$/test.iml" />
+    </modules>
+  </component>
+</project>

src/test/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/../.." vcs="Git" />
+  </component>
+</project>

src/test/.idea/workspace.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ChangeListManager">
+    <list default="true" id="ac272b64-2dd1-434f-b5b7-3d63bb85f743" name="Changes" comment="" />
+    <option name="SHOW_DIALOG" value="false" />
+    <option name="HIGHLIGHT_CONFLICTS" value="true" />
+    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
+    <option name="LAST_RESOLUTION" value="IGNORE" />
+  </component>
+  <component name="Git.Settings">
+    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$/../.." />
+  </component>
+  <component name="ProjectColorInfo"><![CDATA[{
+  "associatedIndex": 2
+}]]></component>
+  <component name="ProjectId" id="3GD0Hh7SguEkean0jp165yqgvdT" />
+  <component name="ProjectViewState">
+    <option name="hideEmptyMiddlePackages" value="true" />
+    <option name="showLibraryContents" value="true" />
+  </component>
+  <component name="PropertiesComponent"><![CDATA[{
+  "keyToString": {
+    "ModuleVcsDetector.initialDetectionPerformed": "true",
+    "RunOnceActivity.ShowReadmeOnStart": "true",
+    "git-widget-placeholder": "main",
+    "ignore.virus.scanning.warn.message": "true",
+    "kotlin-language-version-configured": "true",
+    "last_opened_file_path": "D:/uni_t4/HW-02-git-and-java-practice/src/test"
+  }
+}]]></component>
+  <component name="SharedIndexes">
+    <attachedChunks>
+      <set>
+        <option value="bundled-jdk-9823dce3aa75-bf35d07a577b-intellij.indexing.shared.core-IU-252.23892.409" />
+      </set>
+    </attachedChunks>
+  </component>
+  <component name="TaskManager">
+    <task active="true" id="Default" summary="Default task">
+      <changelist id="ac272b64-2dd1-434f-b5b7-3d63bb85f743" name="Changes" comment="" />
+      <created>1783490746045</created>
+      <option name="number" value="Default" />
+      <option name="presentableId" value="Default" />
+      <updated>1783490746045</updated>
+    </task>
+    <servers />
+  </component>
+</project>