AC自动机

class AC {
public:
    int next[maxn][26], lst[maxn], fail[maxn], val[maxn];
    int sz, root;
    void init() {
        root = sz = 0;
        for (int i=0; i<26; ++i)
            next[sz][i] = 0;
        val[sz] = 0;
        sz = 1;
    }
    inline int getid(char ch) {
        return ch-'a';
    }
    inline int newnode() {
        for (int i=0; i<26; ++i)
            next[sz][i] = 0;
        val[sz] = 0;
        return sz++;
    }
    void insert(char s[]) {
        int rt, i, id, len;
        rt = 0; len = strlen(s);
        for (i=0; i<len; ++i) {
            id = getid(s[i]);
            if (!next[rt][id]) next[rt][id] = newnode();
            rt = next[rt][id];
        }
        val[rt]++;
    }
    void build() {
        queue<int> q;
        int i, rt, id;
        fail[root] = root;
        lst[root] = root;
        for (i=0; i<26; ++i) {
            if (!next[root][i]) next[root][i] = root;
            else {
                fail[next[root][i]] = root;
                q.push(next[root][i]);
                lst[next[root][i]] = val[fail[next[root][i]]] ? fail[next[root][i]] : lst[fail[next[root][i]]];
            }

        }
        while (!q.empty()) {
            rt = q.front(); q.pop();
            for (i=0; i<26; ++i) {
                if (!next[rt][i]) next[rt][i] = next[fail[rt]][i];
                else {
                    fail[next[rt][i]] = next[fail[rt]][i];
                    q.push(next[rt][i]);
                    lst[next[rt][i]] = val[fail[next[rt][i]]] ? fail[next[rt][i]] : lst[fail[next[rt][i]]];
                }
            }
        }
    }
    int query(char s[]) {
        int i, rt, tmp, now = 0, res = 0, len = strlen(s);
        for (i=0; i<len; ++i) {
            now = next[now][getid(s[i])];
            tmp = now;
            while (tmp) {
                res += val[tmp];
                val[tmp] = 0;
                tmp = lst[tmp];
            }
        }
        return res;
    }
};