HDU 2222 Keyword Search（AC自动机）

题意：

让你找在匹配串中出现了多少个模式串，AC自动机模板题。贴个模板。

代码：

////  Created by  CQU_CST_WuErli//  Copyright (c) 2015 CQU_CST_WuErli. All rights reserved.//// #include<bits/stdc++.h>#include <iostream>#include <cstring>#include <cstdio>#include <cstdlib>#include <cctype>#include <cmath>#include <string>#include <vector>#include <list>#include <map>#include <queue>#include <stack>#include <set>#include <algorithm>#include <sstream>#define CLR(x) memset(x,0,sizeof(x))#define OFF(x) memset(x,-1,sizeof(x))#define MEM(x,a) memset((x),(a),sizeof(x))#define ALL(x) x.begin(),x.end()#define AT(i,v) for (auto &i:v)#define For_UVa if (kase!=1) cout << endl#define BUG cout << "I am here" << endl#define lookln(x) cout << #x << "=" << x << endl#define look(x) cout << #x << "=" << x#define SI(a) scanf("%d",&a)#define SII(a,b) scanf("%d%d",&a,&b)#define SIII(a,b,c) scanf("%d%d%d",&a,&b,&c)#define Lson l,mid,rt<<1#define Rson mid+1,r,rt<<1|1#define Root 1,n,1#define BigInteger bignconst int MAX_L=2005;// For BigIntegerconst int INF_INT=0x3f3f3f3f;const long long INF_LL=0x7fffffff;const int MOD=1e9+7;const double eps=1e-9;const double pi=acos(-1);typedef long long  ll;using namespace std;char s[60];char t[1001000];const int maxn=5e5+10;const int maxv=50;int have[maxn],fail[maxn];int nxt[maxn][maxv];struct ACAutoMaton {    int cnt,root;    int ID_cnt;    map<char,int> ID;    void init() {        cnt=ID_cnt=0;        ID.clear();        root=newNode();    }    int newNode() {        for (int i=0;i<26;i++) {            nxt[cnt][i]=-1;        }        have[cnt++]=0;        return cnt-1;    }    int getID(char x) {        return x-'a';    }    void insert(char buf[]) {        int len=strlen(buf);        int now=root;        for (int i=0;i<len;i++) {            int id=getID(buf[i]);            if (nxt[now][id]==-1) nxt[now][id]=newNode();            now=nxt[now][id];        }        have[now]++;    }    void build() {        fail[root]=root;        queue<int> q;        for (int i=0;i<26;i++) {            if (nxt[root][i]==-1) {                nxt[root][i]=root;            }            else {                fail[nxt[root][i]]=root;                q.push(nxt[root][i]);            }        }        while (!q.empty()) {            int u=q.front();q.pop();            for (int i=0;i<26;i++) {                int& v=nxt[u][i];                if (v==-1) {                    v=nxt[fail[u]][i];                }                else {                    fail[v]=nxt[fail[u]][i];                    q.push(v);                }            }        }    }    int find(char buf[]) {        int len=strlen(buf);        int now=root;        int ret=0;        for (int i=0;i<len;i++) {            int id=getID(buf[i]);            now=nxt[now][id];            int tmp=now;            while (tmp!=root) {                ret+=have[tmp];                have[tmp]=0;                tmp=fail[tmp];            }        }        return ret;    }};int main(){#ifdef LOCAL    freopen("C:\\Users\\john\\Desktop\\in.txt","r",stdin);//  freopen("C:\\Users\\john\\Desktop\\out.txt","w",stdout);#endif    int T_T,n; cin >> T_T;    while (T_T--) {        ACAutoMaton ac;        ac.init();        cin >> n;        for (int i=1;i<=n;i++) {            scanf("%s",s);            ac.insert(s);        }        scanf("%s",t);        ac.build();        cout << ac.find(t) << endl;    }    return 0;}