HashMap模板

import java.io.*;
import java.util.*;
class Main{
    static class Node{
        char val;
        int count;
        Map<Character, Node> children;
        Node(){}
        Node(char val){
            this.val = val;
        }
    }
    static Node root;
    public static void insert(String s){
        Node node = root;
        for(int i = 0; i < s.length(); i++){
            char c = s.charAt(i);
            if(node.children == null) node.children = new HashMap();
            if(!node.children.containsKey(c)) node.children.put(c, new Node(c));
            node = node.children.get(c);
        }
        node.count++;
    }

    public static int search(String s){
        Node node = root;
        for(int i = 0; i < s.length(); i++){
            char c = s.charAt(i);
            if(node.children == null || !node.children.containsKey(c)) return 0;
            node = node.children.get(c);
        }
        return node.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 Node();
        for(int i = 0; i < n; i++){
            s = read.readLine().split(" ");
            if("I".equals(s[0])){
                insert(s[1]);
            }else{
                log.write(search(s[1]) + "\n");
            }
        }
        log.flush();
    }
}

y总模板

import java.io.*;
class Main{
    static BufferedReader read = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter log  = new BufferedWriter(new OutputStreamWriter(System.out));
    static int N = 100010, idx = 0;
    static int[][] trie = new int[N][26];
    static int[] cnt = new int[N];

    public static void insert(char[] cs){
        int p = 0;
        for(int i = 0; i < cs.length; i++){
            int t = cs[i] - 'a';
            if(trie[p][t] == 0) trie[p][t] = ++idx;
            p = trie[p][t];
        }
        cnt[p]++;
    }

    public static int query(char[] cs){
        int p = 0;
        for(int i = 0; i < cs.length; i++){
            int t = cs[i] - 'a';
            if(trie[p][t] == 0) return 0;
            p = trie[p][t];
        }
        return cnt[p];
    }

    public static void main(String[] args) throws Exception{
        int t = Integer.valueOf(read.readLine());
        while(t-- > 0){
            String[] s = read.readLine().split(" ");
            switch(s[0]){
                case "I":
                    insert(s[1].toCharArray());
                    break;
                case "Q":
                    log.write(query(s[1].toCharArray()) + "\n");
                    break;
            }
        }
        log.flush();
    }
}