Trie模板

/*==================================================*\ 
  [Trie] 字典树
  support:
        - insert O(L)
        - query O(L)
        - delete O(L) 
  Trie[i]存储第i个节点的信息:
        next[j]: 下一个字符为j时 对应的节点编号 
        fa: 父亲节点编号
        cnt: 字符出现次数  
\*==================================================*/

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include <string>
using namespace std;
//----------------------------------------------
#define CL(a,num) memset(a,num,sizeof(a));
#define BtoA(x,y) memcpy(x,y,sizeof(x)); 
#define eps  1e-12
#define inf  0x7fffffff
typedef    __int64    LL;
//----------------------------------------------
const int Node_max = 100000 + 5;

struct Node {
    int next[26];
    // including a...z
    int fa, cnt, flag;    
} Trie[Node_max];
// root = Trie[0]
int Trie_size;
#define t_s Trie_size

int Trie_ins(char str[]) {
    int len = strlen(str);
    int tmp = 0;
    for(int i = 0; i < len; ++i) {
        if(!Trie[tmp].next[str[i] - 'a']) {
            Trie[tmp].next[str[i] - 'a'] = ++t_s;    
            Trie[t_s].fa = tmp;
        }
        tmp = Trie[tmp].next[str[i] - 'a'];
    }
    return ++Trie[tmp].cnt;
    // let the appear_times of str increase then return it
}
int Trie_query(char str[]) {
    //return the appear_times of str
    int len = strlen(str);
    int tmp = 0;
    for(int i = 0; i < len; ++i) {
        if(!Trie[tmp].next[str[i] - 'a'])
            return -1;    // if can't find str
        tmp = Trie[tmp].next[str[i] - 'a'];
    }
    return Trie[tmp].cnt;
}
int Trie_del(char str[]) {
    int len = strlen(str);
    int tmp = 0;
    for(int i = 0; i < len; ++i) {
        if(!Trie[tmp].next[str[i] - 'a'])
            return -1; // if can't find str
        tmp = Trie[tmp].next[str[i] - 'a'];    
    }
    return --Trie[tmp].cnt; 
    // let the appear_times of str decrease then return it
}
int main() {
    char str[20];
    while(true) {
        int op;
        cin >> op;
        switch(op) {
            case 0: //ins
                cin >> str;
                cout << Trie_ins(str) << endl;
                break;
            case 1: //query
                cin >> str;
                cout << Trie_query(str) << endl;
                break;
            case 2: //del
                cin >> str;
                cout << Trie_del(str) << endl;
                break;
        }
    }
    return 0;    
}