Example #1
0
/**
 * Insert the value into subtree.
 */
_avl_tree_insert_result_t _avl_tree_insert_avlnode(
    const _avl_tree_t* cpt_avl_tree, _avlnode_t* pt_root, const void* cpv_value)
{
    _avl_tree_insert_result_t t_insert_result;
    bool_t           b_result = false;

    assert(cpt_avl_tree != NULL);
    assert(cpv_value != NULL);
    assert(_avl_tree_is_inited(cpt_avl_tree));

    /* if root is NULL then allocate memory */
    if(pt_root == NULL)
    {
        pt_root = _alloc_allocate(
            (_alloc_t*)&cpt_avl_tree->_t_allocator, _AVL_TREE_NODE_SIZE(_GET_AVL_TREE_TYPE_SIZE(cpt_avl_tree)), 1);
        assert(pt_root != NULL);
        _avl_tree_init_elem_auxiliary((_avl_tree_t*)cpt_avl_tree, pt_root);

        pt_root->_pt_left = pt_root->_pt_right = NULL;
        pt_root->_un_height = 0;
        t_insert_result._pt_adjust = pt_root;
        t_insert_result._pt_new = pt_root;
        b_result = _GET_AVL_TREE_TYPE_SIZE(cpt_avl_tree);
        _GET_AVL_TREE_TYPE_COPY_FUNCTION(cpt_avl_tree)(pt_root->_pby_data, cpv_value, &b_result);
        assert(b_result);

        return t_insert_result;
    }

    /* compare the value and current node */
    /* if value < current node then insert into left subtree */
    b_result = _GET_AVL_TREE_TYPE_SIZE(cpt_avl_tree);
    _avl_tree_elem_compare_auxiliary(cpt_avl_tree, cpv_value, pt_root->_pby_data, &b_result);
    if(b_result)
    {
        t_insert_result = _avl_tree_insert_avlnode(cpt_avl_tree, pt_root->_pt_left, cpv_value);
        pt_root->_pt_left = t_insert_result._pt_adjust;
        pt_root->_pt_left->_pt_parent = pt_root;

        pt_root = _avl_tree_rebalance(pt_root);
        t_insert_result._pt_adjust = pt_root;

        return t_insert_result;
    }
    /* else insert into right subtree */
    else
    {
        t_insert_result = _avl_tree_insert_avlnode(cpt_avl_tree, pt_root->_pt_right, cpv_value);
        pt_root->_pt_right =  t_insert_result._pt_adjust;
        pt_root->_pt_right->_pt_parent = pt_root;

        pt_root = _avl_tree_rebalance(pt_root);
        t_insert_result._pt_adjust = pt_root;

        return t_insert_result;
    }
}
Example #2
0
/*
 * Erase an element in an avl tree from specificed position.
 */
void _avl_tree_erase_pos(_avl_tree_t* pt_avl_tree, _avl_tree_iterator_t it_pos)
{
    _avlnode_t* pt_parent = NULL;
    _avlnode_t* pt_cur = NULL;
    bool_t      b_result = false;

    assert(pt_avl_tree != NULL);
    assert(_avl_tree_is_inited(pt_avl_tree));
    assert(_avl_tree_iterator_belong_to_avl_tree(pt_avl_tree, it_pos));
    assert(!_avl_tree_iterator_equal(it_pos, _avl_tree_end(pt_avl_tree)));
    
    pt_cur = (_avlnode_t*)_AVL_TREE_ITERATOR_COREPOS(it_pos);
    pt_parent = pt_cur->_pt_parent;

    /* delete node X express deleting */
    if (pt_cur->_pt_left == NULL && pt_cur->_pt_right == NULL) {
        if (pt_parent == &pt_avl_tree->_t_avlroot) {
            /*
             *  P       P
             *  |   =>   
             *  X
             */
            pt_parent->_pt_parent = NULL;
        } else if (pt_cur == pt_parent->_pt_left) {
            /*
             *    P       P
             *   /   =>   
             *  X
             */
            pt_parent->_pt_left = NULL;
        } else {
            /*
             *   P         P
             *    \   =>  
             *     X
             */
            pt_parent->_pt_right = NULL;
        }
    } else if (pt_cur->_pt_left != NULL && pt_cur->_pt_right == NULL) {
        if (pt_parent == &pt_avl_tree->_t_avlroot) {
            /*
             *   P          P
             *   |          |
             *   X     =>   L
             *  /
             * L
             */
            pt_parent->_pt_parent = pt_cur->_pt_left;
            pt_parent->_pt_parent->_pt_parent = pt_parent;
        } else if (pt_cur == pt_parent->_pt_left) {
            /*
             *     P          P
             *    /          /
             *   X     =>   L
             *  /
             * L
             */
            pt_parent->_pt_left = pt_cur->_pt_left;
            pt_parent->_pt_left->_pt_parent = pt_parent;
        } else {
            /*
             *  P           P
             *   \           \
             *    X   =>      L
             *   /
             *  L
             */
            pt_parent->_pt_right = pt_cur->_pt_left;
            pt_parent->_pt_right->_pt_parent = pt_parent;
        }
    } else if (pt_cur->_pt_left == NULL && pt_cur->_pt_right != NULL) {
        if (pt_parent == &pt_avl_tree->_t_avlroot) {
            /*
             *     P             P
             *     |             |
             *     X     =>      R
             *      \
             *       R
             */
            pt_parent->_pt_parent = pt_cur->_pt_right;
            pt_parent->_pt_parent->_pt_parent = pt_parent;
        } else if (pt_cur == pt_parent->_pt_right) {
            /*
             *   P             P
             *    \             \
             *     X     =>      R
             *      \
             *       R
             */
            pt_parent->_pt_right = pt_cur->_pt_right;
            pt_parent->_pt_right->_pt_parent = pt_parent;
        } else {
            /*
             *    P              R
             *   /              /
             *  X       =>     R
             *   \
             *    R
             */
            pt_parent->_pt_left = pt_cur->_pt_right;
            pt_parent->_pt_left->_pt_parent = pt_parent;
        }
    } else {
        _avlnode_t* pt_parenttmp = NULL;
        _avlnode_t* pt_curtmp = NULL;

        if (pt_parent == &pt_avl_tree->_t_avlroot) {
            pt_curtmp = _avl_tree_get_min_avlnode(pt_cur->_pt_right);
            if (pt_cur == pt_curtmp->_pt_parent) {
                /*
                 *     P              P
                 *     |              | 
                 *     X       =>     B
                 *    / \            / \
                 *   A   B          A   C
                 *        \
                 *         C
                 */
                /* pt_curtmp express B */
                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_parent = pt_curtmp;

                pt_parent = pt_curtmp;
            } else {
                /*
                 *     P              P
                 *     |              | 
                 *     X       =>     S
                 *    / \            / \
                 *   A   B          A   B
                 *      / \            / \
                 *     S   C          D   C
                 *      \
                 *       D
                 */
                /* pt_curtmp express S; pt_parenttmp express B */
                pt_parenttmp = pt_curtmp->_pt_parent;
                pt_parenttmp->_pt_left = pt_curtmp->_pt_right;
                if (pt_parenttmp->_pt_left != NULL) {
                    pt_parenttmp->_pt_left->_pt_parent = pt_parenttmp;
                }

                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_right = pt_cur->_pt_right;
                pt_curtmp->_pt_right->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_parent = pt_curtmp;

                pt_parent = pt_parenttmp;
            }
        } else if (pt_cur == pt_parent->_pt_left) {
            pt_curtmp = _avl_tree_get_min_avlnode(pt_cur->_pt_right);
            if (pt_cur == pt_curtmp->_pt_parent) {
                /*
                 *       P              P
                 *      /              / 
                 *     X       =>     B
                 *    / \            / \
                 *   A   B          A   C
                 *        \
                 *         C
                 */
                /* pt_curtmp express B */
                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_left = pt_curtmp;

                pt_parent = pt_curtmp;
            } else {
                /*
                 *       P              P
                 *      /              / 
                 *     X       =>     S
                 *    / \            / \
                 *   A   B          A   B
                 *      / \            / \
                 *     S   C          D   C
                 *      \
                 *       D
                 */
                /* pt_curtmp express S; pt_parenttmp express B */
                pt_parenttmp = pt_curtmp->_pt_parent;
                pt_parenttmp->_pt_left = pt_curtmp->_pt_right;
                if (pt_parenttmp->_pt_left != NULL) {
                    pt_parenttmp->_pt_left->_pt_parent = pt_parenttmp;
                }

                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_right = pt_cur->_pt_right;
                pt_curtmp->_pt_right->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_left = pt_curtmp;

                pt_parent = pt_parenttmp;
            }
        } else {
            pt_curtmp = _avl_tree_get_min_avlnode(pt_cur->_pt_right);
            if (pt_cur == pt_curtmp->_pt_parent) {
                /*
                 *      P            P
                 *       \            \
                 *        X     =>     B
                 *       / \          / \
                 *      A   B        A   C
                 *           \
                 *            C
                 */
                /* pt_curtmp express B */
                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_right = pt_curtmp;

                pt_parent = pt_curtmp;
            } else {
                /*
                 *      P            P
                 *       \            \
                 *        X     =>     S
                 *       / \          / \
                 *      A   B        A   B
                 *         / \          / \
                 *        C   D        C   D
                 *       / \          / \
                 *      S   E        F   E
                 *       \
                 *        F
                 */
                /* pt_curtmp express S; pt_parenttmp express C */
                pt_parenttmp = pt_curtmp->_pt_parent;
                pt_parenttmp->_pt_left = pt_curtmp->_pt_right;
                if (pt_parenttmp->_pt_left != NULL) {
                    pt_parenttmp->_pt_left->_pt_parent = pt_parenttmp;
                }

                pt_curtmp->_pt_left = pt_cur->_pt_left;
                pt_curtmp->_pt_left->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_right = pt_cur->_pt_right;
                pt_curtmp->_pt_right->_pt_parent = pt_curtmp;
                pt_curtmp->_pt_parent = pt_cur->_pt_parent;
                pt_curtmp->_pt_parent->_pt_right = pt_curtmp;

                pt_parent = pt_parenttmp;
            }
        }
    }

    /* rebalance until to root */
    if (pt_parent != &pt_avl_tree->_t_avlroot) {
        _avlnode_t* pt_newcur = pt_parent;
        pt_parent = pt_newcur->_pt_parent;
        while (pt_parent != &pt_avl_tree->_t_avlroot) {
            if (pt_newcur == pt_parent->_pt_left) {
                pt_parent->_pt_left = _avl_tree_rebalance(pt_parent->_pt_left);
                pt_parent->_pt_left->_pt_parent = pt_parent;
            } else {
                pt_parent->_pt_right = _avl_tree_rebalance(pt_parent->_pt_right);
                pt_parent->_pt_right->_pt_parent = pt_parent;
            }

            pt_newcur = pt_parent;
            pt_parent = pt_newcur->_pt_parent;
        }
    }

    /* rebalance root */
    if (pt_parent->_pt_parent != NULL) {
        pt_parent->_pt_parent = _avl_tree_rebalance(pt_parent->_pt_parent);
        pt_parent->_pt_parent->_pt_parent = pt_parent;
    }

    /* destroy node */
    b_result = _GET_AVL_TREE_TYPE_SIZE(pt_avl_tree);
    _GET_AVL_TREE_TYPE_DESTROY_FUNCTION(pt_avl_tree)(pt_cur->_pby_data, &b_result);
    assert(b_result);
    _alloc_deallocate(&pt_avl_tree->_t_allocator, pt_cur,
        _AVL_TREE_NODE_SIZE(_GET_AVL_TREE_TYPE_SIZE(pt_avl_tree)), 1);
    pt_avl_tree->_t_nodecount--;
    if (pt_avl_tree->_t_nodecount == 0) {
        pt_avl_tree->_t_avlroot._pt_parent = NULL;
        pt_avl_tree->_t_avlroot._pt_left = &pt_avl_tree->_t_avlroot;
        pt_avl_tree->_t_avlroot._pt_right = &pt_avl_tree->_t_avlroot;
    } else {
        pt_avl_tree->_t_avlroot._pt_left = _avl_tree_get_min_avlnode(pt_avl_tree->_t_avlroot._pt_parent);
        pt_avl_tree->_t_avlroot._pt_right = _avl_tree_get_max_avlnode(pt_avl_tree->_t_avlroot._pt_parent);
    }
}