HDU-1251 难题统计（Tire模板题，数组模拟写法）

#include<iostream>
#include<algorithm>
#include<cstring>
 using namespace std;
 const int maxn=400009;
    struct tire{
        int ch[maxn][26];
        int val[maxn];
        int sz;
        void init(){
            sz=1;
            memset(ch[0],0,sizeof(ch[0]));
            val[0]=0;
        }
        int idx(char c){return c-‘a‘;}
        void insert(char *s){
            int u=0;
            int n=strlen(s);
            for(int i=0;i<n;i++){
                int c=idx(s[i]);
                if(!ch[u][c]){
                    memset(ch[sz],0,sizeof(ch[sz]));
                    val[sz]=0;
                    ch[u][c]=sz++;
                }
                val[u]++;
                u=ch[u][c];
            }
            val[u]++;
        }
        int query(char *s){
            int u=0;
            int n=strlen(s);
            for(int i=0;i<n;i++){
                int c=idx(s[i]);
                if(!ch[u][c])    return 0;
                u=ch[u][c];
            }
            return val[u];
        }
    }tire;
 int main()
 {
     char s[20];
     tire.init();
     while(gets(s)&&s[0]!=0)    tire.insert(s);
     while(scanf("%s",&s)!=EOF)  printf("%d\n",tire.query(s));
    return 0;
 }