/* Remove the left tree under the node from the tree */
void bitree_rem_left(BiTree * tree, BiTreeNode * node) {
BiTreeNode ** position;
// For the situation of tree is empty
if (bitree_size(tree) == 0)
return;
// Determine where to remove nodes
if (node == NULL)
position = & tree -> root;
else
position = & node -> left;
if (position != NULL) {
bitree_rem_left(tree, *position);
bitree_rem_right(tree, * position);
if (tree -> destroy != NULL) {
tree -> destroy ((* position) -> data);
}
free( *position);
*position == NULL;
tree -> size--;
}
return;
}
void bitree_rem_right(BiTree * tree, BiTreeNode * node)
{
BiTreeNode **position;
/*****************************************************************************
* Do not allow removal from an empty tree. *
*****************************************************************************/
if (bitree_size(tree) == 0)
return;
/*****************************************************************************
* Determine where to remove nodes. *
*****************************************************************************/
if (node == NULL)
position = &tree->root;
else
position = &node->right;
/*****************************************************************************
* Remove the nodes. *
*****************************************************************************/
if (*position != NULL) {
bitree_rem_left(tree, *position);
bitree_rem_right(tree, *position);
if (tree->destroy != NULL) {
/***********************************************************************
* Call a user-defined function to free dynamically allocated data. *
***********************************************************************/
tree->destroy((*position)->data);
}
free(*position);
*position = NULL;
/**************************************************************************
* Adjust the size of the tree to account for the removed node. *
**************************************************************************/
tree->size--;
}
return;
}
void bitree_destroy(BiTree * tree)
{
/*****************************************************************************
* Remove all the nodes from the tree. *
*****************************************************************************/
bitree_rem_left(tree, NULL);
/*****************************************************************************
* No operations are allowed now, but clear the structure as a precaution. *
*****************************************************************************/
memset(tree, 0, sizeof(BiTree));
return;
}
int main(int argc, char **argv) {
BiTree tree;
BiTreeNode *node;
int i;
/*****************************************************************************
* *
* Initialize the binary tree. *
* *
*****************************************************************************/
bitree_init(&tree, free);
/*****************************************************************************
* *
* Perform some binary tree operations. *
* *
*****************************************************************************/
fprintf(stdout, "Inserting some nodes\n");
if (insert_int(&tree, 20) != 0)
return 1;
if (insert_int(&tree, 10) != 0)
return 1;
if (insert_int(&tree, 30) != 0)
return 1;
if (insert_int(&tree, 15) != 0)
return 1;
if (insert_int(&tree, 25) != 0)
return 1;
if (insert_int(&tree, 70) != 0)
return 1;
if (insert_int(&tree, 80) != 0)
return 1;
if (insert_int(&tree, 23) != 0)
return 1;
if (insert_int(&tree, 26) != 0)
return 1;
if (insert_int(&tree, 5) != 0)
return 1;
fprintf(stdout, "Tree size is %d\n", bitree_size(&tree));
fprintf(stdout, "(Preorder traversal)\n");
print_preorder(bitree_root(&tree));
i = 30;
if ((node = search_int(&tree, i)) == NULL) {
fprintf(stdout, "Could not find %03d\n", i);
}
else {
fprintf(stdout, "Found %03d...Removing the left tree below it\n", i);
bitree_rem_left(&tree, node);
fprintf(stdout, "Tree size is %d\n", bitree_size(&tree));
fprintf(stdout, "(Preorder traversal)\n");
print_preorder(bitree_root(&tree));
}
i = 99;
if ((node = search_int(&tree, i)) == NULL) {
fprintf(stdout, "Could not find %03d\n", i);
}
else {
fprintf(stdout, "Found %03d...Removing the right tree below it\n", i);
bitree_rem_right(&tree, node);
fprintf(stdout, "Tree size is %d\n", bitree_size(&tree));
fprintf(stdout, "(Preorder traversal)\n");
print_preorder(bitree_root(&tree));
}
i = 20;
if ((node = search_int(&tree, i)) == NULL) {
fprintf(stdout, "Could not find %03d\n", i);
}
else {
fprintf(stdout, "Found %03d...Removing the right tree below it\n", i);
bitree_rem_right(&tree, node);
fprintf(stdout, "Tree size is %d\n", bitree_size(&tree));
fprintf(stdout, "(Preorder traversal)\n");
print_preorder(bitree_root(&tree));
}
i = bitree_is_leaf(bitree_root(&tree));
fprintf(stdout, "Testing bitree_is_leaf...Value=%d (0=OK)\n", i);
i = bitree_is_leaf(bitree_left((bitree_root(&tree))));
fprintf(stdout, "Testing bitree_is_leaf...Value=%d (0=OK)\n", i);
i = bitree_is_leaf(bitree_left(bitree_left((bitree_root(&tree)))));
fprintf(stdout, "Testing bitree_is_leaf...Value=%d (1=OK)\n", i);
i = bitree_is_leaf(bitree_right(bitree_left((bitree_root(&tree)))));
fprintf(stdout, "Testing bitree_is_leaf...Value=%d (1=OK)\n", i);
fprintf(stdout, "Inserting some nodes\n");
if (insert_int(&tree, 55) != 0)
return 1;
if (insert_int(&tree, 44) != 0)
return 1;
if (insert_int(&tree, 77) != 0)
return 1;
if (insert_int(&tree, 11) != 0)
return 1;
fprintf(stdout, "Tree size is %d\n", bitree_size(&tree));
fprintf(stdout, "(Preorder traversal)\n");
print_preorder(bitree_root(&tree));
fprintf(stdout, "(Inorder traversal)\n");
print_inorder(bitree_root(&tree));
fprintf(stdout, "(Postorder traversal)\n");
print_postorder(bitree_root(&tree));
/*****************************************************************************
* *
* Destroy the binary tree. *
* *
*****************************************************************************/
fprintf(stdout, "Destroying the tree\n");
bitree_destroy(&tree);
return 0;
}
/* Destroy a binary tree */
void bitree_destroy (BiTree * tree){
bitree_rem_left(tree, NULL);
memset(tree, 0. sizeof(BiTree));
return;
}