HD2222 Keywords Search(AC自动机入门题)

然而还不是很懂=_=

 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #include <cstdio>
 #include <queue>
 using namespace std;
 const int Max = +;
 char str[Max];
 struct node
 {
     int cnt;
     struct node * Next[];
     struct node * fail;
     void init()
     {
         for (int i = ; i < ; i++)
             Next[i] = NULL;
         cnt = ;
         fail = NULL;
     }
 };
 node * root;
 void Insert()
 {
     node * p = root;
     int len = strlen(str);
     for (int i = ; i < len; i++)
     {
         int id = str[i] - 'a';
         if (p->Next[id] == NULL)
         {
             p->Next[id] = new node();
             p->Next[id]->init();
         }
         p = p->Next[id];
     }
     p->cnt++;
 }
 void getFail()
 {
     node * p = root, *temp, *son;
     queue<struct node * > que;
     que.push(p);
     while (!que.empty())
     {
         temp = que.front();
         que.pop();
         for (int i = ; i < ; i++)
         {
             son = temp->Next[i];
             if (son != NULL)
             {
                 if (temp == root)
                 {
                     son->fail = root;
                 }
                 else
                 {
                     p = temp->fail;
                     while (p)
                     {
                         if (p->Next[i])
                         {
                             son->fail = p->Next[i];
                             break;
                         }
                         p = p->fail;
                     }
                     if (!p)
                         son->fail = root;
                 }
                 que.push(son);
             }
         }
     }
 }
 void querry()
 {
     int len, cnt = ;
     len = strlen(str);
     node * p, * temp;
     p = root;
     for (int i = ; i < len; i++)
     {
         int pos = str[i] - 'a';
         while (!p->Next[pos] && p != root)
             p = p->fail;
         p = p->Next[pos];
         if (!p)
             p = root;
         temp = p;
         while (temp != root)
         {
             if (temp->cnt >= )
             {
                 cnt += temp->cnt;
                 temp->cnt = -;
             }
             else
                 break;
             temp = temp->fail;
         }
     }
     printf("%d\n", cnt);
 }
 int main()
 {
     int test, n;
     scanf("%d", &test);
     while (test--)
     {
         root = new node();
         root->init();
         root->fail = NULL;
         scanf("%d", &n);
         getchar();
         for (int i = ; i < n; i++)
         {
             gets(str);
             Insert();
         }
         getFail();
         gets(str);
         querry();
     }
     return ;
 }