题目描述

blablabla

样例

blablabla

算法1

Java 代码

import java.io.*;
import java.util.*;
class Main{
    static class TrieNode{
        public int count;
        public TrieNode[] children;
        public TrieNode() {
            children = new TrieNode[26];
            count = 0;
        }
    }
    private static TrieNode root;

    public static void insert(String s){
        int n = s.length();
        TrieNode p = root;
        for(int i = 0; i < n; i++){
            int index = (int)(s.charAt(i) - 'a');
            if(p.children[index] == null){
                p.children[index] = new TrieNode();
            }
            p = p.children[index] ;
        }
        p.count++;
    }

    public static int search(String s){
        int n = s.length();
        TrieNode p = root;
        for(int i = 0; i < n; i++){
            int index = (int)(s.charAt(i) - 'a');
            if(p.children[index] == null){
                return 0;
            }
            p = p.children[index];
        }
        return p.count;
    }

    static BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter log  = new BufferedWriter(new OutputStreamWriter(System.out));
    public static void main(String[] args) throws Exception{
        int n = Integer.valueOf(read.readLine());
        String[] s;
        root = new TrieNode();
        for(int i = 0; i < n; i++){
            s = read.readLine().split(" ");
            if("I".equals(s[0])){
                insert(s[1]);
            }else if("Q".equals(s[0])){
                log.write(search(s[1]) + "\n");
            }
        }
        log.flush();
    }
}