How to determine whether a binary tree is complete?

Question

A complete binary tree is defined as a binary tree in which every level, except possibly the deepest, is completely filled. At deepest level, all nodes must be as far left a

Answer 1

//Helper function

int depth (struct tree * n)
{
   int ld,rd;

   if (n == NULL) return 0;

   ld=depth(n->left);
   ld=depth(n->right);

   if (ld>rd)
      return (1+ld);
   else
      return (1+rd);

}


//Core function

int isComplete (struct tree * n)
{
   int ld,rd;

   if (n == NULL) return TRUE;

   ld=depth(n->left);
   rd=depth(n->right);

   return(ld==rd && isComplete(n->left) && isComplete(n->right));

}