void double_tree(tree_node* T)
{
/*
For each node in a binary search tree,
create a new duplicate node, and insert
the duplicate as the left child of the original node.
The resulting tree should still be a binary search tree.
So the tree...
2
/ \
1 3
Is changed to...
2
/ \
2 3
/ /
1 3
/
1
*/
if(T!=NULL)
{
tree_node * l_change_node = T -> left;
tree_node * r_change_node = T ->right;
tree_node * add_node = new tree_node(T->data);
add_node -> left = T->left;
T->left = add_node;
double_tree(l_change_node);
double_tree(r_change_node);
}
}
void double_tree(bst *b)
{
if(!b)
return;
bst *dup = new_tree(b->val);
dup->left = b->left;
b->left = dup;
if(b->left->left)
double_tree(b->left->left);
if(b->right)
double_tree(b->right);
}
//left sided doubling or one sided doubling
void double_tree(bst *root) {
bst *oldptr;
if(root == 0) return;
//NOTE : Here we do not return anything we utilize stack
//feature not to avoid communication
double_tree(root->left);
double_tree(root->right);
//store the in oldptr
oldptr = root->left;
//Update load new
root->left = insert_node(root->data);
//store old again for consistency purpose restore the old value
root->left->left = oldptr;
//we cannot use above tric in faltten as we know that we have to suplicate the strucutre only once but in flatten example we have to make count about how many levels/count we should maintain in order to append the data i.e. right pointer/old_ptr
}
int main(int argc, char *argv[])
{
struct bitree *tree;
int cnt;
tree = build(DEFAULT_TREE_SIZE);
if (!tree) {
fprintf(stderr, "build tree error\n");
exit(EXIT_FAILURE);
}
traverse_dump(tree, TRAVE_PREORDER);
traverse_dump(tree, TRAVE_INORDER);
traverse_dump(tree, TRAVE_POSTORDER);
traverse_dump(tree, TRAVE_LEVELORDER);
fprintf(stdout, "\nmirroring the tree\n");
mirror(tree->root);
traverse_dump(tree, TRAVE_LEVELORDER);
mirror(tree->root); /* reverse */
fprintf(stdout, "\ndoubling the tree\n");
double_tree(tree);
traverse_dump(tree, TRAVE_LEVELORDER);
traverse_dump(tree, TRAVE_INORDER);
traverse_dump(tree, TRAVE_PREORDER);
cnt = print_paths(tree->root);
fprintf(stdout, "total %d paths\n", cnt);
exit:
if (visit_list)
dlist_destroy(visit_list);
free(bitree_root(tree)->data);
bitree_destroy(tree);
free(tree);
exit(EXIT_SUCCESS);
}
