P3808 【模板】AC自动机（简单版）

#include<iostream>
#include<cstdio>
#include<queue>
#include<algorithm>
#include<cmath>
#include<ctime>
#include<set>
#include<map>
#include<stack>
#include<cstring>
#pragma GCC optimize(2)
#define inf 2147483647
#define ls rt<<1
#define rs rt<<1|1
#define lson ls,nl,mid,l,r
#define rson rs,mid+1,nr,l,r
#define N 1000010
#define For(i,a,b) for(int i=a;i<=b;++i)
#define p(a) putchar(a)
#define g() getchar()

using namespace std;
int n;
char s[N];
namespace AC{
    int tr[N][26],tot;
    int e[N],fail[N];
    void insert(char *s){
        int u=0;
        for(int i=1;s[i];i++){
            if(!tr[u][s[i]-'a']) tr[u][s[i]-'a']=++tot;
            u=tr[u][s[i]-'a'];
        }
        e[u]++;
    }
    queue<int>q;
    void build(){
        For(i,0,25) 
            if(tr[0][i])
                q.push(tr[0][i]);
        while(!q.empty()){
            int u=q.front();q.pop();
            For(i,0,25)
                if(tr[u][i]){
                    fail[tr[u][i]]=tr[fail[u]][i];
                    q.push(tr[u][i]);
                }
                else
                    tr[u][i]=tr[fail[u]][i];
        }
    }
    int query(char *t){
        int u=0,res=0;
        for(int i=1;t[i];i++){
            u=tr[u][t[i]-'a'];
            for(int j=u;j&&e[j]!=-1;j=fail[j]){
                res+=e[j];
                e[j]=-1;
            }
        }
        return res;
    }
}
void in(int &x){
    int y=1;char c=g();x=0;
    while(c<'0'||c>'9'){if(c=='-')y=-1;c=g();}
    while(c<='9'&&c>='0'){ x=(x<<1)+(x<<3)+c-'0';c=g();}
    x*=y;
}
void o(int x){
    if(x<0){p('-');x=-x;}
    if(x>9)o(x/10);
    p(x%10+'0');
}

int main(){
    in(n);
    For(i,1,n){
        scanf("%s",s+1);
        AC::insert(s);
    }
    scanf("%s",s+1);
    AC::build();
    o(AC::query(s));
    return 0;
}

标签：AC,int,res,tr,P3808,fail,include,模板
来源： https://www.cnblogs.com/war1111/p/11255366.html