binary tree - How to check if all leaves are positioned to the left side of the BinaryTree -

i've been breaking head on tasks lecturer posted prep exams. problem relative easy solve if weren't "own" take on definition of perfect binary tree.

my task this: "check if given binarytree complete (complete = last level needs full and on last level leaves need @ left side of tree. write pointer implementation. below tree complete/perfect tree in definition.

           b       c d     e  f    

nearly info on internet on perfect or full trees don't tackle specific requirement of " leaves need on left side".

what i've done far write class total number of nodes in given tree , compare expected number based on perfect tree formula ( math.pow(2, depth)-1))

here code:

private int numberofnodes =0;   public void printlevelorder(){     linkedblockingqueue<binarynode<e>> stack = new linkedblockingqueue<binarynode<e>>();     binarynode<e> node = root;     stack.offer(node);     while( !stack.isempty()){         node = stack.poll();         if( node != null){             if( node.getleft() != null){                 stack.offer(node.getleft());             }if( node.getright() != null){                 stack.offer(node.getright());             }             numberofnodes++;             system.out.print(node.tostring()+ " ");         }          else{              return;         }       }     system.out.println(); } public int getmaxdepth(binarynode<e> node){     int l =0, r =0;     if( node != null){         if( node.getleft() != null){             l = getmaxdepth(node.getleft());         }if( node.getright() != null){             r = getmaxdepth(node.getright());         }     }     return 1 + math.max(l,r); }  public boolean iscomplete(){     return iscomplete(root);  }  private boolean iscomplete(binarynode<e> node){      int depth = this.getmaxdepth(node);  int expectednodes = (int)(math.pow(2,depth)-1);  system.out.println( numberofnodes + "  -  " + expectednodes);   return false; } 

what understand question have check complete binary tree doing level order traversal starting root.

during traversal, once find node not full node (a node full node if both left , right children not empty), following nodes must leaf nodes.

if node has empty left child, right child must empty.