hdoj 2222

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

第一道 AC自动机。。。。。trie树的建立 和 AC自动机的查询，，可作模版。。。

解题思路：AC的应用。。。直接模版。。

#include <iostream>
#include<cstring>
using namespace std;
struct point {
   struct point *final;
   struct point *next[26];
    int count;
    point(){
        final =NULL;
        count =0;
        memset(next,NULL,sizeof(next));
    }
}*q[500005];

char str[55];
char tt[1000005];
int head, tail;

void build_trie(char *str, point *root){
    point *p = root;
    int i=0,index;
    while(str[i]){
        index = str[i]-'a';
        if(p->next[index]==NULL) p->next[index] = new point();
        p = p->next[index];
        i++;
    }
    p->count++;
}

void get_final(point *root){
    int i;
    root->final = NULL;
    q[head++] = root;
    while(head!=tail){
        point *temp = q[tail++];
        point *p = NULL;
        for(i=0;i<26;i++){
            if(temp->next[i]!=NULL){
                if(temp==root) temp->next[i]->final=root;
                else{
                    p = temp->final;
                    while(p!=NULL){
                        if(p->next[i]!=NULL){
                            temp->next[i]->final = p->next[i];
                            break;
                        }
                        p = p->final;
                    }
                    if(p==NULL) temp->next[i]->final=root;
                }
                q[head++] = temp->next[i];
            }
        }
    }
}

int requry(point *root){
    int i =0,cnt=0,index;
    //int len = strlen(t);
    point *p =root;
    while(tt[i]){
        index = tt[i]-'a';
        while(p->next[index]==NULL&&p!=root)  p= p->final;
        p = p->next[index];
        p=(p==NULL)? root:p;
        point *temp =p;
        while(temp!=root&&temp->count!=-1){
            //cout<<"------------>"<<endl;
            cnt += temp->count;
            temp->count=-1;
            temp = temp->final;
        }
        i++;
    }

    return cnt;
}
int main()
{
    int t;
    cin>>t;
    while(t--){
        int n;
        head =tail =0;
        point *root = new point();
        cin>>n;
        while(n--){
            cin>>str;
            build_trie(str,root);
        }
        get_final(root);
        cin>>tt;

        cout<<requry(root)<<endl;
    }
    return 0;
}