1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/*
* Trie.h
* Created on: Jan 29, 2015
* This file is part of the Gudhi Library. The Gudhi library
* (Geometric Understanding in Higher Dimensions) is a generic C++
* library for computational topology.
*
* Author(s): David Salinas
*
* Copyright (C) 2014 INRIA Sophia Antipolis-M�diterran�e (France)
*
* 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. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef TRIE_H_
#define TRIE_H_
#include <memory>
#include <vector>
namespace Gudhi {
namespace skbl {
template<typename SkeletonBlockerComplex>
struct Trie{
typedef typename SkeletonBlockerComplex::Vertex_handle Vertex_handle;
typedef typename SkeletonBlockerComplex::Simplex_handle Simplex_handle;
Vertex_handle v;
std::vector<std::shared_ptr<Trie> > childs;
//std::vector<std::unique_ptr<Trie> > childs; -> use of deleted function
private:
const Trie* parent_;
public:
Trie():parent_(0){}
Trie(Vertex_handle v_):v(v_),parent_(0){}
Trie(Vertex_handle v_,Trie* parent):v(v_),parent_(parent){}
bool operator==(const Trie& other) const{
return (v == other.v) ;
}
void add_child(Trie* child){
if(child){
std::shared_ptr<Trie> ptr_to_add(child);
childs.push_back(ptr_to_add);
child->parent_ = this;
}
}
typedef typename Simplex_handle::Simplex_vertex_const_iterator Simplex_vertex_const_iterator;
Trie* make_trie(Simplex_vertex_const_iterator s_it,Simplex_vertex_const_iterator s_end){
if(s_it == s_end) return 0;
else{
Trie* res = new Trie(*s_it);
Trie* child = make_trie(++s_it,s_end);
res->add_child(child);
return res;
}
}
private:
//go down recursively in the tree while advancing the simplex iterator.
//when it reaches a leaf, it inserts the remaining that is not present
void add_simplex_helper(Simplex_vertex_const_iterator s_it,Simplex_vertex_const_iterator s_end){
assert(*s_it == v);
++s_it;
if(s_it==s_end) return ;
if(!is_leaf()){
for(auto child : childs){
if(child->v == *s_it)
return child->add_simplex_helper(s_it,s_end);
}
//s_it is not found and needs to be inserted
}
//not leaf -> remaining of s needs to be inserted
Trie* son_with_what_remains_of_s(make_trie(s_it,s_end));
add_child(son_with_what_remains_of_s);
return;
}
void maximal_faces_helper(std::vector<Simplex_handle>& res) const{
if(is_leaf()) res.push_back(simplex());
else
for(auto child : childs)
child->maximal_faces_helper(res);
}
public:
/**
* adds the simplex to the trie
*/
void add_simplex(const Simplex_handle& s){
if(s.empty()) return;
assert(v==s.first_vertex());
add_simplex_helper(s.begin(),s.end());
}
std::vector<Simplex_handle> maximal_faces() const{
std::vector<Simplex_handle> res;
maximal_faces_helper(res);
return res;
}
/**
* Goes to the root in the trie to consitute simplex
*/
void add_vertices_up_to_the_root(Simplex_handle& res) const{
res.add_vertex(v);
if(parent_)
parent_->add_vertices_up_to_the_root(res);
}
Simplex_handle simplex() const{
Simplex_handle res;
add_vertices_up_to_the_root(res);
return res;
}
bool is_leaf() const{
return childs.empty();
}
bool is_root() const{
return parent_==0;
}
const Trie* parent() {
return parent_;
}
void remove_leaf() {
assert(is_leaf);
if(!is_root())
parent_->childs.erase(this);
}
/**
* true iff the simplex corresponds to one node in the trie
*/
bool contains(const Simplex_handle& s) const{
Trie const* current = this;
if(s.empty()) return true;
if(current->v != s.first_vertex()) return false;
auto s_pos = s.begin();
++s_pos;
while(s_pos != s.end() && current != 0){
bool found = false;
for(const auto child : current->childs){
if(child->v == *s_pos) {
++s_pos;
current = child.get();
found = true;
break;
}
}
if(!found) return false;
}
return current!=0;
}
Trie* go_bottom_left(){
if(is_leaf())
return this;
else
return (*childs.begin())->go_bottom_left();
}
friend std::ostream& operator<<(std::ostream& stream, const Trie& trie){
stream<< "T( "<< trie.v<< " ";
for(auto t : trie.childs)
stream << *t ;
stream<<")";
return stream;
}
};
}
}
#endif /* TRIE_H_ */
|
