hdu 1251统计难题

做了几道Trie了，这个题做过之后，让我对Trie又有的许多新的认识，真正的理解了插入和查询的整个过程。

// File Name: hdu1251.cpp// Author: Toy// Created Time: 2013年05月08日 星期三 09时17分28秒#include <iostream>#include <cstdio>#include <cstring>#include <vector>#include <cctype>#include <cmath>#include <string>#include <algorithm>#include <cstdlib>#include <iomanip>#include <list>#include <map>#include <set>#include <deque>#include <stack>#include <utility>#include <bitset>#define L(x) x << 1#define R(x) x << 1 | 1using namespace std;const int sigma_size = 26;const int maxnode = 10 * 50000 + 10;string s, tt;bool flag;struct Trie {    int ch[maxnode][sigma_size];    int val[maxnode];    int sz;    void clear ( ) { sz = 1; memset ( ch[0], 0, sizeof ( ch[0] ) ); }    int idx ( char c ) { return c - 'a'; }    void insert ( string s, int v ) {int u = 0, n = s.length ();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]++;    }    void find ( string s ) {flag = 1;int u = 0, n = s.length ();for ( int i = 0; i < n; ++i ) {    if ( s[i] == '\0' ) {flag = 0;break;    }    int c = idx ( s[i] );    if ( !ch[u][c] ) {flag = 0;        break;    }    u = ch[u][c];}if ( flag ) cout << val[u] << endl;else cout << "0" << endl;    }}trie;int main ( ) {    trie.clear();    while ( getline ( cin, s ) ) {if ( s != "" ) trie.insert ( s, 1 );else {    while ( getline ( cin, tt ) ) {trie.find ( tt );    }}    }    return 0;}