Create ac-automaton.cc

string/ac-automaton.cc

@@ -0,0 +1,86 @@
+#include "../include.hh"
+
+void solve(vector<string> ss, string t) {
+    int n = ss.size();
+    vector<vector<int>> trie(1, vector<int>(26));
+    vector<int> tag(1);
+    vector<int> id(1);
+    vector<int> alias(n, -1);
+    int last = 0;
+    // build trie for ss
+    for (int i = 0; i < n; ++i) {
+        auto&& s = ss[i];
+        int curr = 0;
+        for (auto&& c : s) {
+            int x = c - 'a';
+            if (!trie[curr][x])
+                trie[curr][x] = ++last,
+                tag.push_back({}),
+                id.push_back({}),
+                trie.push_back(vector<int>(26));
+            curr = trie[curr][x];
+        }
+        if (!tag[curr]) id[curr] = i;
+        else alias[i] = id[curr];
+        tag[curr] = 1;
+    }
+
+
+    // build fail
+    vector<int> fail(last + 1);
+    vector<vector<int>> suc(last + 1);
+    deque<pair<int, int>> dq;
+    for (int i = 0; i < 26; ++i) {
+        if (trie[0][i]) dq.emplace_back(trie[0][i], trie[0][i]), suc[0].push_back(trie[0][i]);
+    }
+    while (dq.size()) {
+        popfront(dq, c, rt);
+        for (int i = 0; i < 26; ++i) {
+            if (trie[c][i]) {
+                fail[trie[c][i]] = trie[fail[c]][i];
+                suc[trie[fail[c]][i]].push_back(trie[c][i]);
+                dq.emplace_back(trie[c][i], rt);
+            } else {
+                trie[c][i] = trie[fail[c]][i];
+            }
+        }
+    }
+
+
+    // match t
+    vector<int> oc(last + 1);
+    int curr = 0;
+    for (auto&& c : t) {
+        int x = c - 'a';
+        if (!trie[curr][x]) curr = fail[curr];
+        curr = trie[curr][x];
+        oc[curr] += 1;
+    }
+
+
+    // collect result
+    vector<int> res(n);
+    auto dfs = [&] (auto dfs, int cur) -> int {
+        int cnt = oc[cur];
+        for (auto&& c : suc[cur]) {
+            cnt += dfs(dfs, c);
+        }
+        if (cnt && tag[cur]) {
+            res[id[cur]] += cnt;
+        }
+        return cnt;
+    };
+    dfs(dfs, 0);
+    for (int i = 0; i < n; ++i) {
+        if (alias[i] != -1) cout << res[alias[i]];
+        else cout << res[i];
+        cout << endl;
+    }
+}
+
+int main() {
+    read(int, n);
+    readvec(string, ss, n);
+    read(string, t);
+    solve(ss, t);
+}