implement triangle method

src/main/java/MainExercises.java

@@ -19,9 +19,20 @@ 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) {
+        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 == 0 || j == 0 || i == j || i == n-1)
+                    triangle[i][j] = '*';
+                else
+                    triangle[i][j] = ' ';
+            }
 
-        // todo
-        return null;
+        }
+        return triangle;
 
     }