TADM2E 3.21

<pre> bool compare(struct node* a, struct node* b) {

 // 1. both empty -> true
 if (a==NULL && b==NULL) return(true);   

// 2. both non-empty -> compare them

 else if (a!=NULL && b!=NULL) {
   return(
     a->data == b->data &&
     compare(a->left, b->left) &&
     compare(a->right, b->right)
   );
 }

 // 3. one empty, one not -> false
 else return(false);

} </pre> --Max 06:41, 25 June 2010 (EDT)