1 /* Et-forest data structure implementation. 2 Copyright (C) 2002, 2003, 2004, 2005, 2007, 2010 3 Free Software Foundation, Inc. 4 5 This program is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program; see the file COPYING3. If not see 17 <http://www.gnu.org/licenses/>. */ 18 19 /* This package implements ET forest data structure. Each tree in 20 the structure maintains a tree structure and offers logarithmic time 21 for tree operations (insertion and removal of nodes and edges) and 22 poly-logarithmic time for nearest common ancestor. 23 24 ET tree stores its structure as a sequence of symbols obtained 25 by dfs(root) 26 27 dfs (node) 28 { 29 s = node; 30 for each child c of node do 31 s = concat (s, c, node); 32 return s; 33 } 34 35 For example for tree 36 37 1 38 / | \ 39 2 3 4 40 / | 41 4 5 42 43 the sequence is 1 2 4 2 5 3 1 3 1 4 1. 44 45 The sequence is stored in a slightly modified splay tree. 46 In order to support various types of node values, a hashtable 47 is used to convert node values to the internal representation. */ 48 49 #ifndef _ET_TREE_H 50 #define _ET_TREE_H 51 52 #ifdef __cplusplus 53 extern "C" { 54 #endif /* __cplusplus */ 55 56 /* The node representing the node in an et tree. */ 57 struct et_node 58 { 59 void *data; /* The data represented by the node. */ 60 61 int dfs_num_in, dfs_num_out; /* Number of the node in the dfs ordering. */ 62 63 struct et_node *father; /* Father of the node. */ 64 struct et_node *son; /* The first of the sons of the node. */ 65 struct et_node *left; 66 struct et_node *right; /* The brothers of the node. */ 67 68 struct et_occ *rightmost_occ; /* The rightmost occurrence. */ 69 struct et_occ *parent_occ; /* The occurrence of the parent node. */ 70 }; 71 72 struct et_node *et_new_tree (void *data); 73 void et_free_tree (struct et_node *); 74 void et_free_tree_force (struct et_node *); 75 void et_free_pools (void); 76 void et_set_father (struct et_node *, struct et_node *); 77 void et_split (struct et_node *); 78 struct et_node *et_nca (struct et_node *, struct et_node *); 79 bool et_below (struct et_node *, struct et_node *); 80 struct et_node *et_root (struct et_node *); 81 82 #ifdef __cplusplus 83 } 84 #endif /* __cplusplus */ 85 86 #endif /* _ET_TREE_H */ 87