P5840 [COCI2015]Divljak

https://www.luogu.com.cn/record/102334989

Luogu/P5840/P5840.cpp

@@ -0,0 +1,184 @@
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <string>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5,
+          M = 2e6 + 5;
+
+int n, q, cnt, root, end[N], c[M];
+std::vector<int> g[M];
+int id[M], rid[M], fa[M], dep[M], siz[M], son[M], top[M];
+
+struct node {
+    int val;
+    int child[26], fail;
+
+    node()
+        : val(0), fail(0) {
+        std::fill(std::begin(child), std::end(child), 0);
+    }
+} tr[M];
+
+void insert(std::string s, int id) {
+    int cur = root;
+
+    for (char c : s) {
+        if (!tr[cur].child[c - 'a']) {
+            tr[cur].child[c - 'a'] = ++cnt;
+        }
+
+        cur = tr[cur].child[c - 'a'];
+    }
+
+    end[id] = cur;
+}
+
+void build() {
+    std::queue<int> q;
+
+    for (int i = 0; i < 26; i++) {
+        if (tr[root].child[i]) {
+            q.emplace(tr[root].child[i]);
+        }
+    }
+
+    while (!q.empty()) {
+        int cur = q.front();
+        q.pop();
+
+        for (int i = 0; i < 26; i++) {
+            if (tr[cur].child[i]) {
+                tr[tr[cur].child[i]].fail = tr[tr[cur].fail].child[i];
+                q.emplace(tr[cur].child[i]);
+            } else {
+                tr[cur].child[i] = tr[tr[cur].fail].child[i];
+            }
+        }
+    }
+}
+
+void dfs1(int u, int f) {
+    fa[u] = f;
+    dep[u] = dep[f] + 1;
+    siz[u] = 1;
+    son[u] = -1;
+
+    for (int v : g[u]) {
+        if (v == f) continue;
+
+        dfs1(v, u);
+        siz[u] += siz[v];
+
+        if (son[u] == -1 || siz[son[u]] < siz[v]) son[u] = v;
+    }
+}
+
+void dfs2(int u, int t) {
+    static int cnt = 0;
+
+    rid[id[u] = ++cnt] = u;
+    top[u] = t;
+
+    if (~son[u]) dfs2(son[u], t);
+
+    for (int v : g[u]) {
+        if (v == fa[u] || v == son[u]) continue;
+
+        dfs2(v, v);
+    }
+}
+
+int lca(int u, int v) {
+    while (top[u] != top[v]) {
+        if (dep[top[u]] < dep[top[v]]) std::swap(u, v);
+        u = fa[top[u]];
+    }
+
+    return dep[u] < dep[v] ? u : v;
+}
+
+int lowbit(int x) {
+    return x & -x;
+}
+
+void add(int x, int y) {
+    for (; x <= M; x += lowbit(x)) c[x] += y;
+}
+
+int sum(int x) {
+    int res = 0;
+    for (; x; x -= lowbit(x)) res += c[x];
+    return res;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        std::string s;
+
+        cin >> s;
+
+        insert(s, i);
+    }
+
+    build();
+
+    for (int i = 1; i <= cnt; i++) {
+        g[tr[i].fail].emplace_back(i);
+        g[i].emplace_back(tr[i].fail);
+    }
+
+    dfs1(0, 0);
+    dfs2(0, 0);
+
+    cin >> q;
+
+    while (q--) {
+        int op;
+
+        cin >> op;
+
+        if (op == 1) {
+            std::string p;
+            std::vector<int> v;
+
+            cin >> p;
+
+            int cur = root;
+
+            for (char c : p) {
+                cur = tr[cur].child[c - 'a'];
+                v.emplace_back(cur);
+            }
+
+            std::sort(v.begin(), v.end(), [&](int x, int y) {
+                return id[x] < id[y];
+            });
+
+            for (int x : v) {
+                add(id[x], 1);
+            }
+
+            for (int i = 1; i < v.size(); i++) {
+                add(id[lca(v[i - 1], v[i])], -1);
+            }
+        } else {  // op == 2
+            int x;
+
+            cin >> x;
+
+            cout << sum(id[end[x]] + siz[end[x]] - 1) - sum(id[end[x]] - 1) << endl;
+        }
+    }
+
+    return 0;
+}