ac自动机练习 HihoCoder 1036

题目链接

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ac自动机模板题

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <stdlib.h>
#include <queue>
using namespace std;
const int N = 1e6 + 5;
struct Trie
{
    int next[N][26], ed[N], fail[N], root, pos;
    int newnode()
    {
        for(int i = 0; i < 26; i++)
            next[pos][i] = -1;
        ed[pos] = 0;
        return pos++;
    }
    void init()
    {
        pos = 0;
        root = newnode();
    }
    void insert(string s)
    {
        int n = s.size();
        int now = root;
        for(int i = 0; i < n; i++)
        {
            int b = s[i] - 'a';
            if(next[now][b] == -1) next[now][b] = newnode();
            now = next[now][b];
        }
        ed[now]++;
    }
    void build()
    {
        int now = root;
        queue<int> Q;
        fail[root] = root;
        for(int i = 0; i < 26; i++)
        {
            if(next[now][i] == -1)
                next[now][i] = root;
            else
            {
                fail[next[now][i]] = root;
                Q.push(next[now][i]);
            }
        }
        while(!Q.empty())
        {
            int now = Q.front(); Q.pop();
            for(int i = 0; i < 26; i++)
            {
                if(next[now][i] == -1)
                    next[now][i] = next[fail[now]][i];
                else
                {
                    fail[next[now][i]] = next[fail[now]][i];
                    Q.push(next[now][i]);
                }
            }
        }
    }
    int query(string s)
    {
        int n = s.size();
        int now = root;
        int ans = 0;
        for(int i = 0; i < n; i++)
        {
            int b = s[i]-'a';
            now = next[now][b];
            int tmp = now;
            while(tmp != root)
            {
                if(ed[tmp] >= 0)
                {
                    ans += ed[tmp];
                    ed[tmp] = -1;
                }
                else
                    break;
                tmp = fail[tmp];
            }
        }
        return ans;
    }
};

Trie ac;
int n;
string tmp;
int main()
{
    ac.init();
    scanf("%d", &n);
    for(int i = 0; i < n; i++)
    {
        cin >> tmp;
        ac.insert(tmp);
    }
    getchar();
    ac.build();
    getline(cin,tmp);
    int ans = ac.query(tmp);
    if(ans == 0)
        printf("NO
");
    else
        printf("YES
");
    return 0;
}