HDU 2222 Keywords Search

http://acm.hdu.edu.cn/showproblem.php?pid=2222

AC自动机

#include <stdio.h>
#include <string.h>

const int N=250010,B=26;
int trie[N][26];
int fail[N];
int key[N];
int size;
int que[N];
char s[1000100];
void insert(char *s)
{
    int p=0,i;
    for (i=0;s[i];i++)
    {
        int c=s[i]-'a';
        if (!trie[p][c]) trie[p][c]=++size;
        p=trie[p][c];
    }
    key[p]++;
}
void AC()
{
    int front,rear,u,v,i;
    front=rear=0;
    for (i=0;i<B;i++) if (v=trie[0][i])
    {
        fail[v]=0;
        que[rear++]=v;
    }
    while (front<rear)
    {
        u=que[front++];
        for (i=0;i<B;i++) if (v=trie[u][i])
        {
            fail[v]=trie[fail[u]][i];
            que[rear++]=v;
            //key[v]=key[fail[v]];
        }
        else trie[u][i]=trie[fail[u]][i];
    }
}
int match(char *s)
{
    int cnt=0,p=0,i;
    for (i=0;s[i];i++)
    {
        int c=s[i]-'a';
        p=trie[p][c];
        for (int q=p;q;q=fail[q])
        {
            cnt+=key[q];
            key[q]=0;
        }
    }
    return cnt;
}
int main()
{
    int T;
    scanf("%d",&T);
    int n,i;
    char w[60];
    while (T--)
    {
        memset(trie,0,sizeof(trie));
        memset(key,0,sizeof(key));
        memset(fail,0,sizeof(fail));
        size=0;
        scanf("%d",&n);
        for (i=0;i<n;i++)
        {
            scanf("%s",&w);
            insert(w);
        }
        AC();
        scanf("%s",s);
        int ans=match(s);
        printf("%d\n",ans);
    }
    return 0;
}