hdu 1251（字典树）

思路：一道裸的字典树题。先存代码以后备用。

代码如下：

/**************************************************
 * Author     : xiaohao Z
 * Blog     : http://www.cnblogs.com/shu-xiaohao/
 * Last modified : 2014-04-07 13:10
 * Filename     : testTrie.cpp
 * Description     : 
 * ************************************************/

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <queue>
#include <stack>
#include <vector>
#include <set>
#include <map>
#define MP(a, b) make_pair(a, b)
#define PB(a) push_back(a)

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<unsigned int,unsigned int> puu;
typedef pair<int, double> pid;
typedef pair<ll, int> pli;
typedef pair<int, ll> pil;

const int INF = 0x3f3f3f3f;
const double eps = 1E-6;
const int LEN = 1010;

struct Node{
    int data, num;
    bool flag;
    Node *ch[26];
    Node(){
        memset(ch, 0, sizeof ch);
        flag = num = 0;
        data = -1;
    }
};

class Trie{
    Node* head;
    int getpos(char c){return c-'a';}
public:
    Trie(){head = new Node;}
    void insert(string s, int _data){
        Node* p = head;
        for(int i=0; i<s.size(); i++){
            if(!p->ch[getpos(s[i])]){
                p->ch[getpos(s[i])] = new Node;
            }
            p->num ++;
            p = p->ch[getpos(s[i])];
        }
        p->num ++;
        p->data = _data;
        p->flag = 1;
    }
    
    bool query(string s, int &_data, int &cnt){
        Node* p = head;
        for(int i=0; i<s.size(); i++){
            if(!p->ch[getpos(s[i])]) return false;
            p = p->ch[getpos(s[i])];
        }
        cnt = p->num;
        if(p->flag){
            _data = p->data;
            return true;        
        }
        return false;
    }
};

int main()
{
//    freopen("in.txt", "r", stdin);

    char str[110];
    Trie T;
    while(gets(str)){
        if(strlen(str) == 0) break;
        T.insert(str, 1);
    }
    int data;
    while(cin >> str){
        int cnt = 0;
        T.query(str, data, cnt);
        cout << cnt << endl;
    }
    return 0;
}