HDU 2222 Keywords Search

#include<queue>
#include<cstdio>
#include<cstring>
using namespace std;
char word[55], s[1000010];
struct node
{
node *next[26], *fail;
int cnt;
node()
{
cnt=0;
fail=NULL;
memset(next,NULL,sizeof(next));
}
};
struct ACAutomaton
{
node* root;
void init()
{
root=new node;
root->fail=root;
}
void insert(char* s)
{
node* p=root;
for(int i = 0; s[i]; i++)
{
int c=s[i]-'a';
if(p->next[c] == NULL)
p->next[c] = new node;
p=p->next[c];
}
p->cnt++;
}
void build()
{
queue<node*> q;
for(int i = 0; i < 26; i++)
{
if(root->next[i])
{
q.push(root->next[i]);
root->next[i]->fail=root;
}
}
while(!q.empty())
{
node* u = q.front();
q.pop();
for(int i = 0; i < 26; i++)
{
if(u->next[i])
{
node* v=u->next[i];
q.push(v);
node* t=u->fail;
while(t!=root && t->next[i]==NULL)
t=t->fail;
v->fail=(t->next[i]?t->next[i]:root);
}
}
}
}
int find(char* s)
{
node* cur=root;
int ans=0;
for(int i = 0; s[i]; i++)
{
int c=s[i]-'a';
while(cur!=root && cur->next[c]==NULL)
cur=cur->fail;
cur=(cur->next[c]?cur->next[c]:root);
for(node* p=cur; p->cnt && p!=root; p=p->fail)
{
ans+=p->cnt;
p->cnt=0;
}
}
return ans;
}
};
int main()
{
int T;
scanf("%d",&T);
while(T--)
{
int n;
ACAutomaton AC;
scanf("%d",&n);
AC.init();
for(int i = 1; i <= n; i++)
{
scanf("%s",word);
AC.insert(word);
}
AC.build();
scanf("%s",s);
printf("%d\n",AC.find(s));
}
return 0;
}