Input輸入數據的第一部分是一張單詞表,每行一個單詞,單詞的長度不超過10,它們代表的是老師交給Ignatius統計的單詞,一個空行代表單詞表的結束.第二部分是一連串的提問,每行一個提問,每個提問都是一個字符串.

註意:本題只有一組測試數據,處理到文件結束.
Output對於每個提問,給出以該字符串為前綴的單詞的數量.
Sample Input

banana
band
bee
absolute
acm

ba
b
band
abc

Sample Output

2
3
1
0

模板題

  1 #include<iostream>
  2 using namespace std;
  3 #include<cstdio>
  4 #include<cstring>
  5 #include<queue>
  6 const int maxn = 26;
  7 struct Node{
  8     int mark;
  9     Node *next[maxn];
 10     Node *fail;
 11     Node(){
 
 12         mark = 0;
 13         for(int i=0;i<maxn;i++)
 14             next[i] = NULL;
 15     }
 16     ~Node(){
 17         for(int i=0;i<maxn;i++)
 18             if(next[i]!=NULL)
 19                 delete next[i];
 20     }
 21 };
 22 int v[600];
 23 struct Ac_Machine{
 24     Node *head;
 
 25     char hash(char &s){//壓縮 
 26         return s-‘a‘;
 27     }
 28     Ac_Machine(){
 29         head = NULL;
 30     }
 31     void init(){
 32         if(head!=NULL)
 33             delete head;
 34         head = new Node();
 35     }
 36     void insert(char *s,int len,int num){
 37         Node *pt = head;
 38         for(int i=0;i<len;i++){
 39             int k = hash(s[i]);
 40             if(pt->next[k]==NULL){
 41                 pt->next[k] = new Node();
 42                 pt->next[k]->fail = head;
 43             }
 44             pt = pt->next[k];
 45         }
 46         pt->mark=num;
 47     }
 48     void creat_fail(){
 49         queue<Node*> *team = new queue<Node*>();
 50         head->fail = NULL;
 51         for(int i=0;i<maxn;i++)
 52             if(head->next[i]!=NULL)
 53                 team->push(head->next[i]);
 54         while(!team->empty()){
 55             Node *pt = team->front();
 56             team->pop();
 57             for(int i=0;i<maxn;i++){
 58                 if(pt->next[i]==NULL)
 59                     continue;
 60                 team->push(pt->next[i]);
 61                 Node *pd = pt->fail;
 62                 while(pd!=NULL&&pd->next[i]==NULL)
 63                     pd = pd->fail;
 64                 if(pd!=NULL)
 65                     pt->next[i]->fail = pd->next[i];
 66             }    
 67         } 
 68         delete team;
 69     }
 70     int get(Node *pt){
 71         int ans = 0;
 72         for(int i=0;i<maxn;i++){
 73             if(pt->next[i]==NULL)
 74                 continue;
 75             ans+=get(pt->next[i]);
 76         }    
 77         ans +=pt->mark;
 78         pt->mark = ans;
 79         return ans;
 80     }
 81     int Matching(char *s,int len){
 82         Node *pt = head;
 83         int ans = 0;
 84         for(int i=0;i<len;i++){
 85             int k = hash(s[i]);
 86             if(pt->next[k]==NULL)
 87                 return 0;
 88             pt=pt->next[k];
 89         }
 90         return pt->mark;
 91     }
 92 };
 93 Ac_Machine machine;
 94 char virus[510][210];
 95 char s[20000];
 96 queue<int> ans;
 97 int main(){
 98     machine.init();
 99     while(true){
100         gets(s);
101         int len = strlen(s);
102         if(len==0)
103             break;
104         machine.insert(s,len,1);
105     }
106     machine.get(machine.head);
107     while(scanf("%s",s)!=EOF){
108         printf("%d\n",machine.Matching(s,strlen(s)));
109     }
110     return 0;
111 }

HDU - 1251 統計難題 【字典樹Trie】