ac自动机 模板

自己写的0.0

#include <queue>
#include <cstring>
#include <cstdio>
using namespace std;

struct AC_auto
{
    const static int LetterSize = 26;
    const static int TrieSize = 26 * ( 1e5 + 50);

    int tot,root,fail[TrieSize],end[TrieSize],next[TrieSize][LetterSize];

    int newnode(void)
    {
        memset(next[tot],-1,sizeof(next[tot]));
        end[tot] = 0;
        return tot++;
    }

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

    int getidx(char x)
    {
        return x - 'a';
    }

    void insert(char *ss)
    {
        int len = strlen(ss);
        int now = root;
        for(int i = 0; i < len; i++)
        {
            int idx = getidx(ss[i]);
            if(next[now][idx] == -1)
                next[now][idx] = newnode();
            now = next[now][idx];
        }
        end[now]++;
    }

    void build(void)
    {
        queue<int>Q;
        fail[root] = root;
        for(int i = 0; i < LetterSize; i++)
            if(next[root][i] == -1)
                next[root][i] = root;
            else
                fail[next[root][i]] = root,Q.push(next[root][i]);
        while(Q.size())
        {
            int now = Q.front();Q.pop();
            for(int i = 0; i < LetterSize; 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 match(char *ss)
    {
        int len,now,res;
        len = strlen(ss),now = root,res = 0;
        for(int i = 0; i < len; i++)
        {
            int idx = getidx(ss[i]);
            int tmp = now = next[now][idx];
            while(tmp)
            {
                res += end[tmp];
                end[tmp] = 0;//按题目修改
                tmp = fail[tmp];
            }
        }
        return res;
    }
    void debug()
    {
        for(int i = 0;i < tot;i++)
        {
            printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]);
            for(int j = 0;j < LetterSize;j++)
                printf("%3d",next[i][j]);
            printf("]\n");
        }
    }
};
int main(void)
{


    return 0;
}

 

 从网上扒的：

//======================
// HDU 2222
// 求目标串中出现了几个模式串
//====================
#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string.h>
#include <queue>
using namespace std;

struct Trie
{
    int next[500010][26],fail[500010],end[500010];
    int root,L;
    int newnode()
    {
        for(int i = 0;i < 26;i++)
            next[L][i] = -1;
        end[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'];
        }
        end[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 += end[temp];
                end[temp] = 0;
                temp = fail[temp];
            }
        }
        return res;
    }
    void debug()
    {
        for(int i = 0;i < L;i++)
        {
            printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]);
            for(int j = 0;j < 26;j++)
                printf("%2d",next[i][j]);
            printf("]\n");
        }
    }
};
char buf[1000010];
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;
}

 

struct AC_Auto{
    const static int LetterSize = 26;
    const static int TrieSize = 26 * ( 1e5 + 50); 
    int tot;
    int fail[TrieSize]; 
    int suffixlink[TrieSize]; 

    struct node{
        int ptr[LetterSize];
        int val;
    }tree[TrieSize];

    inline int GetLetterIdx(char c){
        return c - 'a';
    }

    void init_node(node & s){
        memset( s.ptr , 0 , sizeof( s.ptr ) );
        s.val = 0;
    }

    void find(const char * str){
        int len = strlen( str );
        int j = 0;
        for(int i = 0 ; i < len ; ++ i){
            int idx = GetLetterIdx( str[i] );
            while(j && !tree[j].ptr[idx]) j = fail[j];
            j = tree[j].ptr[idx];
            if(suffixlink[j]) minv[i] = suffixlink[j];
            else minv[i] = 0;
        }
    }

    void insert(const char * str){
        int len = strlen( str );
        int cur = 0;
        for(int i = 0 ; i < len ; ++ i){
            int idx = GetLetterIdx( str[i] );
            if(!tree[cur].ptr[idx]){
                tree[cur].ptr[idx] = tot;
                init_node( tree[tot++] );
            }
            cur = tree[cur].ptr[idx];
        }
        if(tree[cur].val == 0) tree[cur].val = len;
        else tree[cur].val = min( tree[cur].val , len );
    }

    void build_fail(){
        queue < int > Q; // 开在栈中 , 如果节点数较多 , 可设为全局变量
        suffixlink[0] = fail[0] = 0;
        for(int i = 0 ; i < LetterSize ; ++ i)
            if(tree[0].ptr[i]){
                int index = tree[0].ptr[i];
                fail[index] = 0 , suffixlink[index] = tree[index].val;
                Q.push( index );
            }
        while(!Q.empty()){
            int x = Q.front() ; Q.pop();
            for(int i = 0 ; i < LetterSize ; ++ i)
                if(tree[x].ptr[i]){
                    int v = tree[x].ptr[i];
                    int j = fail[x];
                    while( j && !tree[j].ptr[i] ) j = fail[j];
                    fail[v] = tree[j].ptr[i];
                    suffixlink[v] = suffixlink[fail[v]];
                    if(suffixlink[v] == 0){
                        if(suffixlink[x]) suffixlink[v] = suffixlink[x] + 1;
                    }
                    else if(suffixlink[x]) suffixlink[v] = min( suffixlink[v] , suffixlink[x] + 1 );
                    if(tree[v].val){
                        if(suffixlink[v]==0) suffixlink[v] = tree[v].val;
                        else suffixlink[v] = min( suffixlink[v] , tree[v].val );
                    }
                    Q.push( v );
                }
        }
    }

    void init(){ tot = 1 ; init_node( tree[0] );}

}ac_auto;