HDU 2222

第一题AC自动机，高仿代码！

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;
const int maxn = 500010;
char str[1000010];
struct ACAutomaton{
    int ch[maxn][26],fail[maxn],val[maxn],last[maxn],sz,root;
    int newnode(){
        memset(ch[sz],0,sizeof(ch[sz]));
        val[sz] = 0;
        return sz++;
    }

    void init(){
        sz = 0;
        root = newnode();
    }

    void insert(char *str){
        int len = strlen(str);
        int now = root;
        for(int i = 0;i < len;i++){
            int &tmp = ch[now][str[i]-'a'];
            if(!tmp)    tmp = newnode();
            now = tmp;
        }
        val[now]++;
    }

    void getfail(){
        queue<int> q;
        fail[root] = root;
        for(int i = 0;i < 26;i++){
            int u = ch[root][i];
            if(u){
                fail[u] = last[u] = 0;
                q.push(u);
            }
        }
        while(!q.empty()){
            int now = q.front();q.pop();
            for(int i = 0;i < 26;i++){
                int u = ch[now][i];
                if(!u)  ch[now][i] = ch[fail[now]][i];
                else{
                    fail[u] = ch[fail[now]][i];
                    last[u] = val[fail[u]] ? fail[u]:last[fail[u]];
                    q.push(u);
                }
            }
        }
    }

    int query(char *str){
        int len = strlen(str);
        int now = root;
        int ret = 0;
        for(int i = 0;i < len;i++){
            now = ch[now][str[i]-'a'];
            int tmp = now;
            while(tmp != root && val[tmp]){
                ret += val[tmp];
                val[tmp] = 0;
                tmp = last[tmp];
            }
        }
        return ret;
    }
}ac;

int main(){
    int kase,n;
    scanf("%d",&kase);
    while(kase--){
        ac.init();
        scanf("%d",&n);
        for(int i = 0;i < n;i++){
            scanf("%s",str);
            ac.insert(str);
        }
        ac.getfail();
        scanf("%s",str);
        printf("%d
",ac.query(str));
    }
    return 0;
}