1 /* Et-forest data structure implementation. 2 Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ 17 18 /* This package implements ET forest data structure. Each tree in 19 the structure maintains a tree structure and offers logarithmic time 20 for tree operations (insertion and removal of nodes and edges) and 21 poly-logarithmic time for nearest common ancestor. 22 23 ET tree stores its structure as a sequence of symbols obtained 24 by dfs(root) 25 26 dfs (node) 27 { 28 s = node; 29 for each child c of node do 30 s = concat (s, c, node); 31 return s; 32 } 33 34 For example for tree 35 36 1 37 / | \ 38 2 3 4 39 / | 40 4 5 41 42 the sequence is 1 2 4 2 5 3 1 3 1 4 1. 43 44 The sequence is stored in a slightly modified splay tree. 45 In order to support various types of node values, a hashtable 46 is used to convert node values to the internal representation. */ 47 48 #ifndef _ET_TREE_H 49 #define _ET_TREE_H 50 51 #include <ansidecl.h> 52 #include <stddef.h> 53 54 #ifdef __cplusplus 55 extern "C" { 56 #endif /* __cplusplus */ 57 58 /* The node representing the node in an et tree. */ 59 struct et_node 60 { 61 void *data; /* The data represented by the node. */ 62 63 int dfs_num_in, dfs_num_out; /* Number of the node in the dfs ordering. */ 64 65 struct et_node *father; /* Father of the node. */ 66 struct et_node *son; /* The first of the sons of the node. */ 67 struct et_node *left; 68 struct et_node *right; /* The brothers of the node. */ 69 70 struct et_occ *rightmost_occ; /* The rightmost occurrence. */ 71 struct et_occ *parent_occ; /* The occurrence of the parent node. */ 72 }; 73 74 struct et_node *et_new_tree (void *data); 75 void et_free_tree (struct et_node *); 76 void et_free_tree_force (struct et_node *); 77 void et_free_pools (void); 78 void et_set_father (struct et_node *, struct et_node *); 79 void et_split (struct et_node *); 80 struct et_node *et_nca (struct et_node *, struct et_node *); 81 bool et_below (struct et_node *, struct et_node *); 82 83 #ifdef __cplusplus 84 } 85 #endif /* __cplusplus */ 86 87 #endif /* _ET_TREE_H */ 88