src/main/java/MainExercises.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 public class MainExercises
 {
     /*
@@ -20,9 +22,20 @@ 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 j=0 ; j<=i ; j++) {
+
+                if (j == 0 || j == i || i == n-1)
+                    triangle[i][j] = '*';
+                else
+                    triangle[i][j] = ' ';
+            }
+        }
+        return triangle;
     }
 
 
@@ -58,8 +71,50 @@ public class MainExercises
            - Number of columns: matrix[0].length (if rectangular)
    */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
-        return null;
+
+        int rows = matrix.length;
+        int columns = matrix[0].length;
+
+        int[] result = new int[rows*columns];
+        int count = 0;
+
+        int top = 0;
+        int bottom = rows - 1;
+        int right = columns - 1;
+        int left = 0;
+
+        while (top <= bottom && left <= right) {
+
+            for(int j = left ; j<=right ; j++) {
+                result[count] = matrix[top][j];
+                count++;
+            }
+            top++;
+
+            for(int i = top ; i<=bottom ; i++) {
+                result[count] = matrix[i][right];
+                count++;
+            }
+            right--;
+
+            if(top <= bottom) {
+                for (int j = right; j >= left; j--) {
+                    result[count] = matrix[bottom][j];
+                    count++;
+                }
+            }
+            bottom--;
+
+            if(left <= right){
+                for (int i = bottom; i >= top; i--) {
+                    result[count] = matrix[i][left];
+                    count++;
+                }
+            }
+            left++;
+
+        }
+        return result;
     }
 
     /*
@@ -91,10 +146,56 @@ public class MainExercises
     */
 
     public int[][] intPartitions(int n) {
-        // todo
-        return null;
+
+
+        ArrayList<int[]> result = new ArrayList<>();
+
+        int[] currentPartition = new int[n];
+
+        int k=0; //اخرین ایندکس  currentPartition
+
+        currentPartition[k] = n;
+
+        while (true) {
+
+            int[] temp = new int[k+1];
+            for(int i=0 ; i<=k ; i++) {
+                temp[i] = currentPartition[i];
+            }
+            result.add(temp);
+
+            int remained = 0;
+            while(k>=0 && currentPartition[k]==1) {
+                remained += currentPartition[k];
+                k--;
             }
 
+            if(k<0)
+                break;
+
+            currentPartition[k]--;
+            remained++;
+
+
+            while (remained > currentPartition[k]) {
+                currentPartition[k+1] = currentPartition[k];
+                remained -= currentPartition[k];
+                k++;
+            }
+
+            currentPartition[k+1] = remained;
+            k++;
+
+        }
+
+        int[][] output = new int[result.size()][];
+        for(int i=0 ; i<result.size() ; i++) {
+            output[i] = result.get(i);
+        }
+
+        return output;
+
+    }
 
     public static void main()
     {