HDU 3065：病毒侵袭持续中（AC自动机）

http://acm.hdu.edu.cn/showproblem.php?pid=3065

题意：中文题意。

思路：直接插入然后用一个数组记录id和cnt，因为n只有1000，可以开一个数组判断第几个字符串出现过的次数，然后输出就好了。

坑点：多组输入！！！然后因为new出来的空间要自己释放，因此需要用一个vector装起来（似乎多此一举），最后delete掉。

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 #include <vector>
 #include <queue>
 using namespace std;
 #define N 1010
 #define M 2000010
 #define TOL 128
 typedef struct Node {
     Node* next[TOL];
     Node* fail;
     int id, cnt;
     Node () {
         for(int i = ; i < TOL; i++) next[i] = NULL;
         id = cnt = ;
         fail = NULL;
     }
 } node;

 char s[N][], str[M];

 class AC_DFA {

 private:
     node* root;
     int ans[N], n;
     vector<node*> dic;

 public:
     AC_DFA(int now) {
         dic.clear();
         root = new Node();
         dic.push_back(root);
         n = now;
         memset(ans, , sizeof(ans));
     }

     ~AC_DFA() {
         for(int i = ; i < dic.size(); i++) delete dic[i];
     }

     void insert(char *s, int id) {
         int len = strlen(s);
         node* now = root;
         for(int i = ; i < len; i++) {
             char c = s[i];
             if(now->next[c] == NULL) now->next[c] = new Node(), dic.push_back(now->next[c]);
             now = now->next[c];
         }
         now->id = id;
         now->cnt++;
     }

     void build() {
         queue<node *> que;
         que.push(root);
         root->fail = NULL;
         while(!que.empty()) {
             node* now = que.front();
             que.pop();
             for(int i = ; i < TOL; i++) {
                 if(now->next[i]) {
                     node* p = now->fail;
                     while(p && p->next[i] == NULL) p = p->fail;
                     if(p) now->next[i]->fail = p->next[i];
                     else now->next[i]->fail = root;
                     que.push(now->next[i]);
                 } else {
                     if(now == root) now->next[i] = root;
                     else now->next[i] = now->fail->next[i];
                 }
             }
         }
     }

     void match(char *s) {
         int len = strlen(s);
         node *now = root, *p;
         for(int i = ; i < len; i++) {
             char c = s[i];
             while(now != root && now->next[c] == NULL)
                 now = now->fail;
             now = now->next[c];
             p = now;
             while(p) {
                 if(p->cnt) ans[p->id] += p->cnt;
                 p = p->fail;
             }
         }
     }

     void print() {
         for(int i = ; i <= n; i++)
             if(ans[i]) printf("%s: %d\n", s[i], ans[i]);
     }

 };

 int main() {
     int n;
     while(~scanf("%d", &n)) {
         AC_DFA ac(n);
         for(int i = ; i <= n; i++) {
             scanf("%s", s[i]);
             ac.insert(s[i], i);
         }
         scanf("%s", str);
         ac.build();
         ac.match(str);
         ac.print();
     }
     return ;
 }