$\newcommand{\O}{\mathrm{O}}$

時間計算量: 構築にかかる時間計算量, 空間計算量は O(σS) (S は文字列の合計の長さとする.) (以下の実装では実際 σ 倍かかるケースは珍しく, 感覚的には O(S) と考えてよい.)
// 使う文字は 31 文字以下の文字コード上で連続する文字の列とする.
template<char START_CHARACTER, unsigned int CHARACTER_SIZE>
class CompressedTrie {
private:
struct node {
string *s;
node **to;
// sub: 部分木に含まれる要素の数, adj: 子の bit 表現, cnt: ここで終わる頂点の数
uint32_t sub, adj, cnt;
node() : s(nullptr), to(nullptr), sub(1u), adj(0u), cnt(1u){}
node(string&& _s, node *v, unsigned int index, uint32_t _sub, uint32_t _cnt)
: s(new string[CHARACTER_SIZE]()), to(new node*[CHARACTER_SIZE]()),
sub(_sub), adj(1u << index), cnt(_cnt){
s[index] = move(_s), to[index] = v;
}
// ~node(){ delete[] s, delete[] to; }
#define lsb(v) (__builtin_ctz(v))
inline unsigned int begin() const { return adj ? lsb(adj) : CHARACTER_SIZE; }
inline unsigned int next(unsigned int cur) const {
cur = adj & ~((1u << (cur + 1u)) - 1u);
return cur ? lsb(cur) : CHARACTER_SIZE;
}
inline static unsigned int end(){ return CHARACTER_SIZE; }
inline bool isExist(const unsigned int v) const { return adj >> v & 1u; }
inline bool isFinal() const { return !s; }
void direct_push(string&& _s, unsigned int index){
if(!s) s = new string[CHARACTER_SIZE](), to = new node*[CHARACTER_SIZE]();
s[index] = move(_s), to[index] = new node(), ++sub, adj |= (1u << index);
}
};
void make_node(string& orgs, unsigned int start, node*& to, bool is_end){
string tmp = orgs.substr(0, start);
orgs.erase(orgs.begin(), orgs.begin() + start);
to = new node(move(orgs), to, orgs[0] - START_CHARACTER, to->sub + is_end, is_end);
orgs = move(tmp);
}
void new_push(const string& s, unsigned int index, node *to){
string _s(s.substr(index, s.size() - index));
to->direct_push(move(_s), s[index] - START_CHARACTER);
}
void new_push(string&& s, unsigned int index, node *to){
s.erase(s.begin(), s.begin() + index);
to->direct_push(move(s), s[0] - START_CHARACTER);
}
template<typename String>
void push(node *cur, String&& news){
if(news.size() == 0u){
++cur->sub, ++cur->cnt;
return;
}
const unsigned int _ls = news.size();
unsigned int index = 0u, prefix;
while(true){
const unsigned int num = news[index] - START_CHARACTER;
if(cur->isExist(num)){
++cur->sub;
string& orgs = cur->s[num];
const unsigned int ls = orgs.size();
for(prefix = 0u; prefix < ls && index < _ls; ++prefix, ++index){
if(orgs[prefix] == news[index]) continue;
make_node(orgs, prefix, cur->to[num], false);
new_push(forward<String>(news), index, cur->to[num]);
return;
}
if(index == _ls){
if(prefix == ls){
++cur->to[num]->sub, ++cur->to[num]->cnt;
return;
}
make_node(orgs, prefix, cur->to[num], true);
return;
}else{
cur = cur->to[num];
}
}else{
new_push(forward<String>(news), index, cur);
return;
}
}
}
// void clear_dfs(node *cur){
// if(!cur) return;
// for(unsigned int i = 0u; i < CHARACTER_SIZE; ++i) if(cur->to) clear_dfs(cur->to[i]);
// delete cur;
// }
public:
node* root;
CompressedTrie() : root(new node()){ --root->cnt; }
// ~CompressedTrie(){ clear_dfs(root); }
// CompressedTrie 木に s を加える
void add(const string& s){ push(root, s); }
void add(string&& s){ push(root, move(s)); }
// 文字列 s がいくつ含まれるか
int query1(const string& s){
if(s.size() == 0u) return root->cnt;
node *cur = root;
int i, d = 0;
while(true){
if(d == (int)s.size()) return cur->cnt;
if(cur->isFinal()) break;
const unsigned int next = s[d] - START_CHARACTER;
if(!cur->isExist(next)) return 0;
for(i = 0; i < (int)cur->s[next].size(); ++i){
if(d + i >= (int)s.size() || s[d + i] != cur->s[next][i]) return 0;
}
d += (int)cur->s[next].size();
cur = cur->to[next];
}
return 0;
}
// 文字列 s を prefix とする文字列はいくつか
int query2(const string& s){
node *cur = root;
int d = 0;
while(true){
if(d >= (int)s.size()) return cur->sub;
if(cur->isFinal()) break;
const unsigned int next = s[d] - START_CHARACTER;
if(!cur->isExist(next)) return 0;
for(int i = 0; i < min((int)cur->s[next].size(), (int)s.size() - d); ++i){
if(s[d + i] != cur->s[next][i]) return 0;
}
d += (int)cur->s[next].size();
cur = cur->to[next];
}
return 0;
}
// 辞書順で文字列 s 以下の文字列はいくつか
int query3(const string& s){
node *cur = root;
int d = 0, res = 0;
while(true){
if(d <= (int)s.size()) res += cur->cnt;
if(d >= (int)s.size() || cur->isFinal()) break;
const unsigned int next = s[d] - START_CHARACTER;
for(unsigned int i = cur->begin(); i < next; i = cur->next(i)){
res += cur->to[i]->sub;
}
if(!cur->isExist(next)) break;
for(int i = 0; i < min((int)cur->s[next].size(), (int)s.size() - d); ++i){
if(s[d + i] < cur->s[next][i]) return res;
else if(s[d + i] > cur->s[next][i]) return res + cur->to[next]->sub;
}
d += (int)cur->s[next].size();
cur = cur->to[next];
}
return res;
}
};
Atcoder : Lexicographical disorder 提出コード(非想定解)