geos/opt/lib/gcc/i686-elf/13.2.0/plugin/include/et-forest.h
2024-03-26 15:15:06 +01:00

86 lines
2.6 KiB
C

/* Et-forest data structure implementation.
Copyright (C) 2002-2023 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* This package implements ET forest data structure. Each tree in
the structure maintains a tree structure and offers logarithmic time
for tree operations (insertion and removal of nodes and edges) and
poly-logarithmic time for nearest common ancestor.
ET tree stores its structure as a sequence of symbols obtained
by dfs(root)
dfs (node)
{
s = node;
for each child c of node do
s = concat (s, c, node);
return s;
}
For example for tree
1
/ | \
2 3 4
/ |
4 5
the sequence is 1 2 4 2 5 3 1 3 1 4 1.
The sequence is stored in a slightly modified splay tree.
In order to support various types of node values, a hashtable
is used to convert node values to the internal representation. */
#ifndef _ET_TREE_H
#define _ET_TREE_H
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/* The node representing the node in an et tree. */
struct et_node
{
void *data; /* The data represented by the node. */
int dfs_num_in, dfs_num_out; /* Number of the node in the dfs ordering. */
struct et_node *father; /* Father of the node. */
struct et_node *son; /* The first of the sons of the node. */
struct et_node *left;
struct et_node *right; /* The brothers of the node. */
struct et_occ *rightmost_occ; /* The rightmost occurrence. */
struct et_occ *parent_occ; /* The occurrence of the parent node. */
};
struct et_node *et_new_tree (void *data);
void et_free_tree (struct et_node *);
void et_free_tree_force (struct et_node *);
void et_free_pools (void);
void et_set_father (struct et_node *, struct et_node *);
void et_split (struct et_node *);
struct et_node *et_nca (struct et_node *, struct et_node *);
bool et_below (struct et_node *, struct et_node *);
struct et_node *et_root (struct et_node *);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _ET_TREE_H */