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;