| 1 | /* Et-forest data structure implementation. |
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| 2 | Copyright (C) 2002-2024 Free Software Foundation, Inc. |
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| 3 | |
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| 4 | This program is free software; you can redistribute it and/or modify |
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| 5 | it under the terms of the GNU General Public License as published by |
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| 6 | the Free Software Foundation; either version 3 of the License, or |
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| 7 | (at your option) any later version. |
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| 8 | |
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| 9 | This program is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | GNU General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU General Public License |
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| 15 | along with this program; see the file COPYING3. If not see |
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| 16 | <http://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | /* This package implements ET forest data structure. Each tree in |
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| 19 | the structure maintains a tree structure and offers logarithmic time |
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| 20 | for tree operations (insertion and removal of nodes and edges) and |
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| 21 | poly-logarithmic time for nearest common ancestor. |
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| 22 | |
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| 23 | ET tree stores its structure as a sequence of symbols obtained |
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| 24 | by dfs(root) |
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| 25 | |
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| 26 | dfs (node) |
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| 27 | { |
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| 28 | s = node; |
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| 29 | for each child c of node do |
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| 30 | s = concat (s, c, node); |
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| 31 | return s; |
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| 32 | } |
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| 33 | |
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| 34 | For example for tree |
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| 35 | |
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| 36 | 1 |
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| 37 | / | \ |
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| 38 | 2 3 4 |
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| 39 | / | |
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| 40 | 4 5 |
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| 41 | |
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| 42 | the sequence is 1 2 4 2 5 3 1 3 1 4 1. |
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| 43 | |
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| 44 | The sequence is stored in a slightly modified splay tree. |
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| 45 | In order to support various types of node values, a hashtable |
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| 46 | is used to convert node values to the internal representation. */ |
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| 47 | |
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| 48 | #ifndef _ET_TREE_H |
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| 49 | #define _ET_TREE_H |
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| 50 | |
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| 51 | #ifdef __cplusplus |
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| 52 | extern "C" { |
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| 53 | #endif /* __cplusplus */ |
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| 54 | |
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| 55 | /* The node representing the node in an et tree. */ |
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| 56 | struct et_node |
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| 57 | { |
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| 58 | void *data; /* The data represented by the node. */ |
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| 59 | |
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| 60 | int dfs_num_in, dfs_num_out; /* Number of the node in the dfs ordering. */ |
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| 61 | |
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| 62 | struct et_node *father; /* Father of the node. */ |
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| 63 | struct et_node *son; /* The first of the sons of the node. */ |
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| 64 | struct et_node *left; |
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| 65 | struct et_node *right; /* The brothers of the node. */ |
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| 66 | |
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| 67 | struct et_occ *rightmost_occ; /* The rightmost occurrence. */ |
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| 68 | struct et_occ *parent_occ; /* The occurrence of the parent node. */ |
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| 69 | }; |
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| 70 | |
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| 71 | struct et_node *et_new_tree (void *data); |
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| 72 | void et_free_tree (struct et_node *); |
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| 73 | void et_free_tree_force (struct et_node *); |
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| 74 | void et_free_pools (void); |
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| 75 | void et_set_father (struct et_node *, struct et_node *); |
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| 76 | void et_split (struct et_node *); |
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| 77 | struct et_node *et_nca (struct et_node *, struct et_node *); |
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| 78 | bool et_below (struct et_node *, struct et_node *); |
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| 79 | struct et_node *et_root (struct et_node *); |
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| 80 | |
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| 81 | #ifdef __cplusplus |
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| 82 | } |
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| 83 | #endif /* __cplusplus */ |
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| 84 | |
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| 85 | #endif /* _ET_TREE_H */ |
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| 86 | |
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