do question 3

src/main/java/MainExercises.java

@@ -1,4 +1,5 @@
 import java.util.ArrayList;
+import java.util.List;
 
 public class MainExercises
 {
@@ -150,11 +151,67 @@ public class MainExercises
         body to use them instead of arrays.
     */
 
+    private static  List<List<Integer>> result;
+    private static  List<Integer> help;
+
+
     public int[][] intPartitions(int n) {
-        // todo
-        return null;
+        result = new ArrayList<>();
+        help = new ArrayList<>();
+
+        findRecursive(n, n);
+
+        int[][] answer = casting(result);
+
+        return answer;
     }
 
+    private static void findRecursive(int target , int max){
+
+        if(target == 0){
+
+            result.add(new ArrayList<>(help));
+            return;
+        }
+
+        for(int i = Math.min(target , max) ; i >= 1 ; i--){
+            help.add(i);
+
+
+            findRecursive(target -i , i);
+
+            help.remove(help.size() -1);
+
+        }
+
+    }
+
+    private  int[][]  casting(List<List<Integer>> input){
+       int n = input.size();
+
+        int[][] answer = new int[n][];
+
+        for(int i = 0 ; i < n ; i++){
+            int k = input.get(i).size();
+            answer[i] =  new int[k];
+
+            for(int j = 0 ; j < k ; j++){
+                answer[i][j] = input.get(i).get(j);
+            }
+
+
+        }
+
+        return answer;
+
+
+
+    }
+
+
+
+
+
 
     public static void main()
     {