HDU 2222 Keywords Search

#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()  //开辟空间
{
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[])  //trie树
{
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()             //失败指针
{
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;  //第一层指向root
Q.push(next[root][i]);        //继续
}
while( !Q.empty() )
{
int now = Q.front();
Q.pop();
for(int i = 0;i < 26;i++)
if(next[now][i] == -1)   //指向失败指针
next[now][i] = next[fail[now]][i];
else
{
fail[next[now][i]]=next[fail[now]][i]; //更新失败指针
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;
}

};

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;
}