AC自动机模板

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在一个字符串中出现模板串的个数
#include <iostream>#include <string.h>#include <stdio.h>#include <algorithm>#include <queue>#include <math.h>#define MOD 1000000007using namespace std;const int N = 1e6+10;const int M = 26;struct Trie{    int next[N][M],end[N],fail[N];    int root,L;    int newNode(){        for(int i = 0; i < M; ++i){            next[L][i] = -1;        }        end[L++] = 0;        return L-1;    }    void init(){        L = 0;        root = newNode();    }    void insert(char buf[]){        int now = root;        for(int i = 0; buf[i]; ++i){            int x = buf[i]-'a';            if(next[now][x] == -1)                next[now][x] = newNode();            now = next[now][x];        }        end[now]++;    }    void build(){        queue<int>Q;        fail[root] = root;        for(int i = 0; i < M; ++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 < M; ++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 now = root;        int res = 0;        for(int i = 0; buf[i]; ++i){            now = next[now][buf[i]-'a'];            int temp = now;            while(temp != root){                res += end[temp];                end[temp] = 0;                temp = fail[temp];            }        }        return res;    }};char buf[N];Trie ac;int main(){    int T;    int n;    scanf("%d",&T);    while(T--){        scanf("%d",&n);        ac.init();        for(int i = 0; i < n; ++i){            scanf("%s",buf);            ac.insert(buf);        }        ac.build();        scanf("%s",buf);        printf("%d\n",ac.query(buf));    }    return 0;}
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