求助! Java全部超时

• 本地能过测试点#1, 提交全部超时
• 求助各位大佬,这道题 Java 不能用数组模拟吗

import java.io.*;
import java.util.*;

public class Main {

    static int N = 3000010;
    static int tree[][]; 
    static int num[];  // 标记拥有该子串的 字符串数量
    static int index = 0;

    // 映射对应asii
    static int getnum(char x){
        if(x >= 'A' && x <= 'Z')  // 大写
            return x - 'A'; 
        else if(x >= 'a'&& x <= 'z') // 小写
            return x - 'a' + 26;
        else
            return x - '0' + 52;    // 数字
    } 

    static void insert(char ch[]) {
        int id = 0;
        for(int i = 0; i < ch.length; i++) {
            int c = getnum(ch[i]);

            if(tree[id][c] == 0)
                tree[id][c] = ++index;

            id = tree[id][c];
            num[id]++;  // 拥有该子串前缀 字符串数量+1
        }

    }

    static int query(char ch[]) {
        int id = 0;
        for(int i = 0; i < ch.length; i++) {
            int c = getnum(ch[i]);

            if(tree[id][c] == 0)
                return 0;

            id = tree[id][c];
        }
        return num[id];
    }

    public static void main(String[] args) throws Exception {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int T = Integer.parseInt(br.readLine());
        tree = new int[N][65];  // 区分大小写
        num = new int[N];

        while(T-- > 0) {
            String str[] = br.readLine().split(" ");

            int n = Integer.parseInt(str[0]);
            int q = Integer.parseInt(str[1]);

            for(int i = 0; i < tree.length; i++)
                Arrays.fill(tree[i], 0);
            Arrays.fill(num, 0);

            // 插入
            while(n-- > 0) 
                insert(br.readLine().toCharArray() );
            // 查询
            while(q-- > 0) {
                int res = query(br.readLine().toCharArray() );
                bw.write(res + "\n");
            }
        }

        bw.flush();
    }
}