#include <iostream>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <limits>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#define INF 0x3f3f3f3f
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxN = 1000000 + 7;
struct AC_automat{
    int trie[maxN][26], tot;
    int fail[maxN], sum[maxN];

    void Clear(int rt)
    {
        for(int i = 0; i < 26; i ++ )
            trie[rt][i] = 0;
        sum[rt] = 0 ;
    }

    void init()
    {
        tot = 0;
        Clear(0);
    }

    void Insert(char *s)
    {
        int rt = 0;
        for(int i = 0; s[i]; i ++ )
        {
            int id = s[i] - 'a';
            if(!trie[rt][id]) { trie[rt][id] = ++ tot; Clear(tot); }
            rt = trie[rt][id];
        }
        sum[rt]++ ;
    }

    void build()
    {
        memset(fail, 0, sizeof(fail));
        queue<int>que;
        for(int i = 0; i < 26; i ++ )
            if(trie[0][i]) que.push(trie[0][i]);
        while(!que.empty())
        {
            int rt = que.front(); que.pop();
            for(int i = 0; i < 26; i ++ )
            {
                if(trie[rt][i])
                {
                    fail[trie[rt][i]] = trie[fail[rt]][i];
                    que.push(trie[rt][i]);
                } else trie[rt][i] = trie[fail[rt]][i];
            }
        }
    }

    int query(char *t)
    {
        int ans = 0;
        int now = 0;
        for(int i = 0; t[i]; i ++ )
        {
            int id = t[i] - 'a';
            now = trie[now][id];
            for(int nex = now; nex && ~sum[nex]; nex = fail[nex])
                ans += sum[nex], sum[nex] = -1;
        }
        return ans;
    }

}ac_auto;
int n;
char s[maxN];
int main()
{
    scanf("%d", &n);
    ac_auto.init();
    for(int i = 0; i < n; i ++ )
    {
        scanf("%s", s);
        ac_auto.Insert(s);
    }
    ac_auto.build();
    scanf("%s", s);
    printf("%d\n", ac_auto.query(s));
    return 0;
}
/*
6
she
her
he
him
his
e
hisheher
 ans = 5:his\she\he\e\her
*/

来源：CSDN

作者：Eve_Miracle*

链接：https://blog.csdn.net/weixin_44049850/article/details/104182836

标签

自动机

int函数

洛谷 P3808 【模板】AC自动机（简单版）

洛谷 P3808 【模板】AC自动机（简单版）