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 = ;
     const static int TrieSize =  * ( 1e5 + );

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

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

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

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

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

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

     return ;
 }

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[][],fail[],end[];
    int root,L;
    int newnode()
    {
        for(int i = ;i < ;i++)
            next[L][i] = -;
        end[L++] = ;
        return L-;
    }
    void init()
    {
        L = ;
        root = newnode();
    }
    void insert(char buf[])
    {
        int len = strlen(buf);
        int now = root;
        for(int i = ;i < len;i++)
        {
            if(next[now][buf[i]-'a'] == -)
                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 = ;i < ;i++)
            if(next[root][i] == -)
                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 = ;i < ;i++)
                if(next[now][i] == -)
                    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 = ;
        for(int i = ;i < len;i++)
        {
            now = next[now][buf[i]-'a'];
            int temp = now;
            while( temp != root )
            {
                res += end[temp];
                end[temp] = ;
                temp = fail[temp];
            }
        }
        return res;
    }
    void debug()
    {
        for(int i = ;i < L;i++)
        {
            printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]);
            for(int j = ;j < ;j++)
                printf("%2d",next[i][j]);
            printf("]\n");
        }
    }
};
char buf[];
Trie ac;
int main()
{
    int T;
    int n;
    scanf("%d",&T);
    while( T-- )
    {
        scanf("%d",&n);
        ac.init();
        for(int i = ;i < n;i++)
        {
            scanf("%s",buf);
            ac.insert(buf);
        }
        ac.build();
        scanf("%s",buf);
        printf("%d\n",ac.query(buf));
    }
    return ;
}

struct AC_Auto{
    const static int LetterSize = ;
    const static int TrieSize =  * ( 1e5 + );
    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 ,  , sizeof( s.ptr ) );
        s.val = ;
    }

    void find(const char * str){
        int len = strlen( str );
        int j = ;
        for(int i =  ; 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] = ;
        }
    }

    void insert(const char * str){
        int len = strlen( str );
        int cur = ;
        for(int i =  ; 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 == ) 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[] = fail[] = ;
        for(int i =  ; i < LetterSize ; ++ i)
            if(tree[].ptr[i]){
                int index = tree[].ptr[i];
                fail[index] =  , suffixlink[index] = tree[index].val;
                Q.push( index );
            }
        while(!Q.empty()){
            int x = Q.front() ; Q.pop();
            for(int i =  ; 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] == ){
                        if(suffixlink[x]) suffixlink[v] = suffixlink[x] + ;
                    }
                    else if(suffixlink[x]) suffixlink[v] = min( suffixlink[v] , suffixlink[x] +  );
                    if(tree[v].val){
                        if(suffixlink[v]==) suffixlink[v] = tree[v].val;
                        else suffixlink[v] = min( suffixlink[v] , tree[v].val );
                    }
                    Q.push( v );
                }
        }
    }

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

}ac_auto;