hihocoder 1036 Trie图

url: http://hihocoder.com/problemset/problem/1036

#include<cstdio>
#include<cstdlib>
#include<queue>
#include<cstring>
using namespace std;
const int max_node=1e6+5,sigma_size=26;
char s[1000005];
struct AhoCorasickAutomata
{
    int ch[max_node][sigma_size],fail[max_node],sz;
    bool val[max_node];
    inline void init()
    {
        sz=1;
        memset(ch[0],0,sizeof(ch[0]));
    }
    inline int idx(char c){return c-'a';}
    void Insert(char *s)
    {
        int u=0,len=strlen(s);
        for(int i=0;i<len;i++)
        {
            int c=idx(s[i]);
            if(!ch[u][c])
            {
                memset(ch[sz],0,sizeof(ch[sz]));
                val[sz]=0;
                ch[u][c]=sz++;
            }
            u=ch[u][c];
        }
        val[u]=1;
    }
    void Getfail()
    {
        queue<int>q;
        for(int i=0;i<sigma_size;i++)
        {
            int u=ch[0][i];
            if(u){fail[u]=0;q.push(u);}
        }
        while(!q.empty())
        {
            int r=q.front();q.pop();
            for(int i=0;i<sigma_size;i++)
            {
                int u=ch[r][i];
                if(!u){ch[r][i]=ch[fail[r]][i];continue;}
                q.push(u);
                int v=fail[r];
                while(v&&!ch[v][i])v=fail[v];
                fail[u]=ch[v][i];
            }
        }
    }
    bool Find(char* s)
    {
        for(int i=0,j=0;s[i];i++)
        {
            int c=idx(s[i]);
            j=ch[j][c];
            if(val[j])return 1;
        }
        return 0;
    }
}ac;
int main()
{
    ac.init();
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%s",s);
        ac.Insert(s);
    }
    ac.Getfail();
    scanf("%s",s);
    puts(ac.Find(s)?"YES":"NO");
    return 0;
}