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
|
#include <cstdint>
#include <forward_list>
#include <map>
#include <memory>
#include <cassert>
#include <iostream>
template <
typename Key
>
class Trie {
public:
typedef std::unique_ptr<Trie> ptr;
Trie():
children_() { }
inline void add(std::forward_list<Key> path) {
this->add(path, path.begin());
}
inline void add(std::forward_list<Key>& path,
typename std::forward_list<Key>::const_iterator curr) {
if ( curr != path.end() ) {
Trie::ptr& trie = this->children_[*curr];
if ( trie ) {
trie->add(path, ++curr);
} else {
trie.reset(new Trie<Key>());
trie->add(path, ++curr);
}
}
}
inline Trie* resolve(std::forward_list<Key> path) const {
return this->resolve(path, path.begin());
}
inline Trie* resolve(
std::forward_list<Key>& path,
typename std::forward_list<Key>::const_iterator curr
) const {
auto trie = this->children_.find(*curr);
if ( trie != this->children_.end() ) {
auto next = ++curr;
if ( next == path.end() ) {
return (*trie).second.get();
} else {
return (*trie).second->resolve(path, next);
}
} else {
return nullptr;
}
}
protected:
std::map<Key, Trie::ptr> children_;
};
int main() {
Trie<uint8_t> test;
test.add(std::forward_list<uint8_t>{1, 2, 3});
test.add(std::forward_list<uint8_t>{1, 2, 4});
test.add(std::forward_list<uint8_t>{2, 1});
test.add(std::forward_list<uint8_t>{2, 1, 1});
assert(test.resolve(std::forward_list<uint8_t>{1, 2}) != nullptr);
assert(test.resolve(std::forward_list<uint8_t>{1, 2, 4}) != nullptr);
assert(test.resolve(std::forward_list<uint8_t>{3}) == nullptr);
}
|
