HDU 5384 字典树、AC自动机

题目：http://acm.hdu.edu.cn/showproblem.php?pid=5384

用字典树、AC自动机两种做法都可以做

 #include<stdio.h>
 #include<string.h>
 #include<string>
 #include<iostream>
 using namespace std;
 struct node{
     int cnt;
     node *next[];
     node(){
         cnt = ;
         for(int i = ;i<;i++)
             next[i] = NULL;
     }
 }*a;
 void insert(char *str){
     node *head = a;
     int len = strlen(str);
     for(int i = ;i<len;i++){
         int temp = str[i]-'a';
         if(head->next[temp] == NULL)
             head->next[temp] = new node;
         head = head->next[temp];
     }
     head->cnt++;
 }
 int find(string t){
     node *head = a;
     int ans = ;
     for(int i = ;i<t.size();i++){
         if(head->next[t[i]-'a']){
             if(head->next[t[i]-'a']->cnt){
                 ans++;

             }
         }else
             break;
         head = head->next[t[i]-'a'];
     }
     head->cnt--;
     return ans;
 }
 int main(){
     int t;
     scanf("%d",&t);
     while(t--){
         a = new node;
         int n;
         scanf("%d",&n);
         char s[];
         for(int i = ;i<n;i++){
             scanf(" %s",s);
             insert(s);
         }
         string des;
         cin >> des;
         int ans = ;
         for(int i = ;i<des.size();i++){
             ans += find(des.substr(i));
         }
         printf("%d\n",ans);
     }
     return ;
 }

字典树

 #include<stdio.h>
 #include<string.h>
 #include<string>
 #include<iostream>
 using namespace std;
 struct node{
     int cnt;
     node *next[];
     node(){
         cnt = ;
         for(int i = ;i<;i++)
             next[i] = NULL;
     }
 }*a;
 void insert(char *str){
     node *head = a;
     int len = strlen(str);
     for(int i = ;i<len;i++){
         int temp = str[i]-'a';
         if(head->next[temp] == NULL)
             head->next[temp] = new node;
         head = head->next[temp];
     }
     head->cnt++;
 }
 int find(string t){
     node *head = a;
     int ans = ;
     for(int i = ;i<t.size();i++){
         if(head->next[t[i]-'a']){
             if(head->next[t[i]-'a']->cnt){
                 ans++;

             }
         }else
             break;
         head = head->next[t[i]-'a'];
     }
     head->cnt--;
     return ans;
 }
 int main(){
     int t;
     scanf("%d",&t);
     while(t--){
         a = new node;
         int n;
         scanf("%d",&n);
         char s[];
         for(int i = ;i<n;i++){
             scanf(" %s",s);
             insert(s);
         }
         string des;
         cin >> des;
         int ans = ;
         for(int i = ;i<des.size();i++){
             ans += find(des.substr(i));
         }
         printf("%d\n",ans);
     }
     return ;
 }

AC自动机