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#1817. 【2017.3 长乐省选集训 Day18 T3】子串

Browse Source 
https://sjzezoj.com/submission/66630
This commit is contained in:
Baoshuo Ren 2022-12-31 22:30:15 +08:00
parent 65fb32fd8d
commit 3e5e81008f
Signed by: baoshuo
GPG Key ID: 00CB9680AB29F51A
1 changed files with 31 additions and 21 deletions
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52
S2OJ/1817/1817.cpp
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@ -19,12 +19,10 @@ class AcAutomaton {
private: private:
struct node { struct node {
int cnt; int cnt;
std::shared_ptr<node> child[26], fail; std::weak_ptr<node> child[26], fail;
node() node()
: cnt(0), fail(nullptr) { : cnt(0) {}
std::fill(std::begin(child), std::end(child), nullptr);
}
}; };
std::shared_ptr<node> root; std::shared_ptr<node> root;
@ -37,16 +35,18 @@ class AcAutomaton {
: root(std::make_shared<node>()), nodes({root}), nodes_id({{root, 0}}) {} : root(std::make_shared<node>()), nodes({root}), nodes_id({{root, 0}}) {}
void insert(std::string s) { void insert(std::string s) {
std::shared_ptr<node> cur = root; auto cur = root;
for (char c : s) { for (char c : s) {
if (cur->child[c - 'a'] == nullptr) { if (auto ptr = cur->child[c - 'a'].lock()) {
cur->child[c - 'a'] = std::make_shared<node>(); cur = ptr;
nodes_id[cur->child[c - 'a']] = nodes.size(); } else {
nodes.emplace_back(cur->child[c - 'a']); ptr = std::make_shared<node>();
cur->child[c - 'a'] = ptr;
nodes_id[ptr] = nodes.size();
nodes.emplace_back(ptr);
cur = ptr;
} }
cur = cur->child[c - 'a'];
} }
cur->cnt++; cur->cnt++;
@ -56,9 +56,9 @@ class AcAutomaton {
std::queue<std::shared_ptr<node>> q; std::queue<std::shared_ptr<node>> q;
for (int i = 0; i < 26; i++) { for (int i = 0; i < 26; i++) {
if (root->child[i] != nullptr) { if (auto ptr = root->child[i].lock()) {
q.emplace(root->child[i]); q.emplace(ptr);
root->child[i]->fail = root; ptr->fail = root;
} else { } else {
root->child[i] = root; root->child[i] = root;
} }
@ -69,12 +69,18 @@ class AcAutomaton {
q.pop(); q.pop();
for (int i = 0; i < 26; i++) { for (int i = 0; i < 26; i++) {
if (cur->child[i] != nullptr) { if (auto ptr = cur->child[i].lock()) {
cur->child[i]->fail = cur->fail->child[i] == nullptr ? root : cur->fail->child[i]; auto cur_fail_ptr = cur->fail.lock(),
cur_fail_ch_ptr = cur_fail_ptr->child[i].lock();
q.emplace(cur->child[i]); ptr->fail = cur_fail_ch_ptr ? cur_fail_ch_ptr : root;
q.emplace(cur->child[i].lock());
} else { } else {
cur->child[i] = cur->fail->child[i] == nullptr ? root : cur->fail->child[i]; auto cur_fail_ptr = cur->fail.lock(),
cur_fail_ch_ptr = cur_fail_ptr->child[i].lock();
cur->child[i] = cur_fail_ch_ptr ? cur_fail_ch_ptr : root;
} }
} }
} }
@ -85,9 +91,11 @@ class AcAutomaton {
std::shared_ptr<node> cur = root; std::shared_ptr<node> cur = root;
for (char c : t) { for (char c : t) {
cur = cur->child[c - 'a'] == nullptr ? root : cur->child[c - 'a']; auto cur_ch_ptr = cur->child[c - 'a'].lock();
for (auto i = cur; i != nullptr && i->cnt != -1; i = i->fail) { cur = cur_ch_ptr ? cur_ch_ptr : root;
for (auto i = cur; i != nullptr && i->cnt != -1; i = i->fail.lock()) {
res += i->cnt; res += i->cnt;
i->cnt = -1; i->cnt = -1;
} }
@ -184,7 +192,9 @@ int main() {
a[i].back() = 1; a[i].back() = 1;
for (auto ch : ac.nodes[i]->child) { for (auto ch : ac.nodes[i]->child) {
a[i][ac.nodes_id[ch]] = ((a[i][ac.nodes_id[ch]] - inv_26) % mod + mod) % mod; auto ptr = ch.lock();
a[i][ac.nodes_id[ptr]] = ((a[i][ac.nodes_id[ptr]] - inv_26) % mod + mod) % mod;
} }
} }