AC自动机模板 hdu2222

#include <bits/stdc++.h>
using namespace std;

struct Aho
{
    int next[500010][26],fail[500010],cnt[500010];
    int root,L;
    int newnode()
    {
        for(int i = 0;i < 26;i++)
            next[L][i] = -1;
        cnt[L++] = 0;
        return L-1;
    }
    void init()
    {
        L = 0;
        root = newnode();
    }
    void insert(char buf[])
    {
        int len=strlen(buf);
        int now=root;
        for(int i = 0;i < len;i++){
            if(next[now][buf[i]-'a'] == -1)
                next[now][buf[i]-'a'] = newnode();
            now = next[now][buf[i]-'a'];
        }
        cnt[now]++;
    }
    void build(){
        queue<int>Q;
        fail[root] = root;
        for(int i = 0;i < 26;i++)
            if(next[root][i] == -1)
                next[root][i] = root;
            else{
                fail[next[root][i]] = root;
                Q.push(next[root][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(char buf[])
    {
        int len = strlen(buf);
        int now = root;
        int res = 0;
        for(int i = 0;i < len;i++){
            now = next[now][buf[i]-'a'];
            int temp = now;
            while( temp != root ){
                res += cnt[temp];
                cnt[temp] = 0;
                temp = fail[temp];
            }
        }
        return res;
    }
//    void debug()
//    {
//        for(int i = 0;i < L;i++){
//            printf("id = %3d,fail = %3d,cnt = %3d,chi = [",i,fail[i],cnt[i]);
//            for(int j = 0;j < 26;j++)
//                printf("%2d",next[i][j]);
//            printf("]
");
//        }
//    }
}aho;

char buf[1000010];
int main()
{
    int T;
    int n;
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        aho.init();
        for(int i = 0;i < n;i++){
            scanf("%s",buf);
            aho.insert(buf);
        }
        aho.build();
        scanf("%s",buf);
        printf("%d
",aho.query(buf));
    }
    return 0;
}
原文地址:https://www.cnblogs.com/lalalatianlalu/p/8360999.html