学步园

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1251

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
struct TrieNode{
    int count;
    struct TrieNode *next[26];
 };
 TrieNode *root=new TrieNode;
 
 void build(char *s){
    TrieNode *head=root;
    int len=strlen(s);
    for(int i=0;i<len;i++){
        if(head->next[s[i]-'a']==NULL){
            head->next[s[i]-'a']=new TrieNode;
            head=head->next[s[i]-'a'];
            for(int i=0;i<26;i++)
                head->next[i]=NULL;
            head->count=1;
        }
        else{
            head=head->next[s[i]-'a'];
            head->count++;
        }

    }

 }
 int search(char *s){
    int len=strlen(s);
    TrieNode *head=root;
    for(int i=0;i<len;i++)
        if(head->next[s[i]-'a']==NULL)
            return 0;
        else
            head=head->next[s[i]-'a'];
    return head->count;
 }
void Delete(TrieNode *p){
    for(int i=0;i<26;i++){
        if(p->next[i]!=NULL)
            delete(p->next[i]);
    }
    free(p);
 }
 int main(){
    char s[20];
    for(int i=0;i<26;i++)
        root->next[i]=NULL;
    root->count=0;
    while(gets(s))
    {
        if(!strcmp(s,""))
        break;

        build(s);
     }
     while(scanf("%s",s)!=EOF)
     {
         printf("%d\n",search(s));
     }
     return 0;
 }