src/main/java/BonusExercises.java

@@ -21,10 +21,99 @@ public class BonusExercises {
      */
     public boolean validateEmail(String email) {
         String regex = ""; // todo
+        int indexAt = 0;
+        int Atnum = 0  ;
+        int datnum = 0 ;
+        int dat1 = 0;
+        int dat2 = 0 ;
+        int emsize = email.length() ;
+        for (int i = 0 ; i < email.length(); i ++)
+        {
+            if (email.charAt(i) == '@')
+            {
+                indexAt = i ;
+                Atnum ++ ;
+
+            }
+            if (email.charAt(i) == ' ')
+            {
+                return false ;
+            }
+        }
+        if (Atnum != 1)
+        {
+            return  false ;
+        }
+        if(indexAt == 0)
+        {
+            return false ;
+        }
+        if (indexAt == 1 && email.charAt(0) == ' ')
+        {
+            return false ;
+        }
+        if (email.charAt(0) == '.' || email.charAt(Atnum-1) == '.')
+        {
+            return false ;
+        }
+        for (int i = 0 ; i <Atnum ; i++)
+        {
+            if (email.charAt(i) == '.')
+            {
+
+                datnum ++ ;
+
+            }
+            if (datnum == 1)
+            {
+                dat1 = i;
+            }
+            if (datnum == 2)
+            {
+                dat2 = i ;
+            }
+        }
+        if (datnum > 1)
+        {
+            return false ;
+        }
+        if(indexAt== (emsize-1))
+        {
+            return false ;
+        }
+        if (indexAt == (emsize-2) && email.charAt(emsize-1) == ' ' )
+        {
+            return false ;
+        }
+        if (email.charAt(indexAt+1) == '-' || email.charAt(emsize-1) == '-')
+        {
+            return false ;
+        }
+        for (int i = indexAt ; i <emsize ; i++)
+        {
+            if (email.charAt(i) == '_')
+            {
+
+                return false;
+
+            }
+        }
+        if(datnum == 2)
+        {
+            if (email.charAt(dat1+1) == '-' || email.charAt(dat2-1) == '-')
+            {
+                return false ;
+            }
+            else {
+                return true ;
+            }
+        }
+
+
         Pattern pattern = Pattern.compile(regex);
         Matcher matcher = pattern.matcher(email);
 
-        return matcher.matches();
+        return true;
     }
 
     /*
@@ -40,7 +129,33 @@ public class BonusExercises {
     */
     public String findDate(String string) {
         // todo
-        return null;
+        int StartIndex  = 0 ;
+        String Final = "" ;
+        boolean CheckNull = true ;
+        String number = "0123456789" ;
+        int StrSize = string.length() ;
+        for (int i = 0 ; i < StrSize ; i ++)
+        {
+            char x = string.charAt(i) ;
+            if(number.indexOf(x) != -1)
+            {
+                StartIndex = i ;
+                CheckNull = false ;
+                break;
+            }
+        }
+        if (CheckNull == true)
+        {
+            return null ;
+        }
+
+
+
+    for (int i = StartIndex ; i <StartIndex+10 ; i ++)
+    {
+         Final = Final + string.charAt(i)   ;
+    }
+        return Final;
     }
 
     /*
@@ -55,18 +170,98 @@ public class BonusExercises {
      */
     public int findValidPasswords(String string) {
         // todo
-        return -1;
+
+        String number = "0123456789" ;
+        String special = "!@#$%^&*" ;
+        int FinalNumber = 0 ;
+
+        int StrSize = string.length() ;
+        for(int i = 0 ; i < StrSize ; i ++)
+        {
+            if(string.charAt(i)==' ') continue;
+
+
+
+            boolean check_upper = false ;
+            boolean check_lower = false ;
+            boolean check_number = false ;
+            boolean check_special = false ;
+            boolean len = false ;
+            char x  = string.charAt(i) ;
+            if (x != ' ' ) {
+                int j = i   ;
+                while (   j < StrSize && string.charAt(j) != ' ') {
+                    char y = string.charAt(j) ;
+                    if (Character.isDigit(y)) {
+                        check_number = true;
+                    }
+                    if (Character.isUpperCase(y)) {
+                        check_upper = true;
+                    }
+                    if (Character.isLowerCase(y)) {
+                        check_lower = true;
+                    }
+                    if (special.indexOf(y) != -1) {
+                        check_special = true;
+                    }
+
+                    j ++ ;
+
+                }
+                if ((j-i)>=8)
+                {
+                    len = true ;
+                }
+                i = j-1 ;
+                if (len && check_lower && check_number && check_special && check_upper)
+                {
+                    FinalNumber ++ ;
+                }
+            }
+
+
+        }
+        return FinalNumber;
     }
 
     /*
         you should return a list of *words* which are palindromic
         by word we mean at least 3 letters with no whitespace in it
+        vv
 
         note: your implementation should be case-insensitive, e.g. Aba -> is palindrome
      */
     public List<String> findPalindromes(String string) {
         List<String> list = new ArrayList<>();
         // todo
+
+        int size = string.length() ;
+        for (int i = 0 ; i < size ; i ++)
+        {
+            if(string.charAt(i)==' ') continue;
+            String pal = "" ;
+            String pal2 = "" ;
+            String pal3 = "" ;
+            String spe = "!?.*," ;
+            int j = i   ;
+
+            while (j < size && string.charAt(j) != ' ' ) {
+                char y = string.charAt(j) ;
+               if (Character.isLetter(y)) {
+                   pal3 = pal3 + y;
+                   pal = Character.toLowerCase(y) + pal;
+                   pal2 = pal2 + Character.toLowerCase(y);
+               }
+                j++ ;
+
+
+            }
+            if (pal2.equals(pal) && pal3.length()>=3)
+            {
+                list.add(pal3) ;
+            }
+            i = j - 1 ;
+        }
         return list;
     }
 

src/main/java/MainExercises.java

@@ -1,5 +1,7 @@
-public class MainExercises
+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 " "
@@ -20,13 +22,23 @@ public class MainExercises
  */
     public char[][] generateTriangle(int n) {
 
-        // todo
+        char[][] triangle = new char[n][];
-        return null;
+        for (int i = 0; i < n; i++) {
+            triangle[i] = new char[i + 1];
+            for (int j = 0; j <= i; j++) {
+                if (i == 0 || j == 0 || i == j || i == (n - 1)) {
+                    triangle[i][j] = '*';
+                } else {
+                    triangle[i][j] = ' ';
+                }
+            }
+        }
+
+        return triangle;
 
     }
 
 
-
     /*
        SPIRAL TRAVERSAL OF A RECTANGULAR MATRIX
 
@@ -57,11 +69,52 @@ public class MainExercises
            - Number of rows:    matrix.length
            - Number of columns: matrix[0].length (if rectangular)
    */
-    public int[] spiralTraversal(int[][] matrix) {
+    public  int[] spiralTraversal(int[][] matrix) {
-        // todo
+        int rows = matrix.length;
-        return null;
+        int col = matrix[0].length;
+
+        int size = 0 ;
+        boolean increase = true;
+        int range = rows * col ;
+        int check = 0 ;
+        int UP = 0 ;
+        int DOWN = rows-1 ;
+        int LEFT = 0 ;
+        int RIGHT = col -1;
+
+       int[] newmat = new int[rows*col] ;
+       while (UP <= DOWN && LEFT<= RIGHT) {
+           for (int j = LEFT; j <= RIGHT; j++) {
+               newmat[size] = matrix[UP][j];
+               size++;
+           }
+
+           UP++;
+           for (int i = UP; i <= DOWN; i++) {
+               newmat[size] = matrix[i][RIGHT ];
+               size++;
+           }
+           RIGHT--;
+           if(UP <= DOWN) {
+               for (int j = RIGHT ; j >= LEFT; j--) {
+                   newmat[size] = matrix[DOWN ][j];
+                   size++;
+               }
+               DOWN--;
+           }
+           if(LEFT <= RIGHT) {
+               for (int i = DOWN ; i >= UP; i--) {
+                   newmat[size] = matrix[i][LEFT];
+                   size++;
+               }
+               LEFT++;
+           }
+
+       }
+        return newmat ;
     }
 
+
     /*
         integer partitioning is a combinatorics problem in discreet maths
         the problem is to generate sum numbers which their summation is the input number
@@ -79,7 +132,7 @@ public class MainExercises
         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.
+        which m  eans 1,2 and 2,1 are not different — they count as the same combination.
 
         You should generate all partitions of the input number.
 
@@ -90,9 +143,41 @@ public class MainExercises
         body to use them instead of arrays.
     */
 
+
     public int[][] intPartitions(int n) {
-        // todo
+       ArrayList <int[]> all = new ArrayList<>() ;
-        return null;
+       ArrayList<Integer>list = new ArrayList<>() ;
+       part(n , n ,list , all);
+       return convertTo2DArray(all) ;
+
+
+    }
+    public static int[][] convertTo2DArray(ArrayList<int[]> all) {
+        int [][] mat = new int [all.size()][] ;
+        for (int i = 0 ; i < all.size() ; i ++ )
+        {
+            mat[i] = all.get(i) ;
+        }
+        return mat;
+    }
+    public static void part(int rem , int max , ArrayList<Integer> list , ArrayList<int []> all )
+    {
+        if (rem == 0)
+        {
+            int[] final1 =  new int [list.size()] ;
+            for (int i = 0 ; i < list.size(); i ++ )
+            {
+                final1[i] = list.get(i) ;
+            }
+            all.add(final1) ;
+            return;
+        }
+        for (int i = Math.min(rem , max) ; i >=1 ; i --  )
+        {
+            list.add(i) ;
+            part(rem-i , i , list, all );
+            list.remove(list.size()-1) ;
+        }
     }