非常好奇第2题的数据

用Trie树实现了一把，但是只有 50% 正确率，实在找不到原因在哪😅

有无佬帮忙看看

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws IOException {
        Scanner scanner = new Scanner(new BufferedInputStream(System.in));
        BufferedOutputStream outputStream = new BufferedOutputStream(System.out);
//        PrintWriter writer = new PrintWriter(outputStream);
//        int n = scanner.nextInt();
        scanner.nextLine();
        String s = scanner.nextLine();

        Trie trie = new Trie();
        trie.mergeString(s);
        byte[] ans = new byte[s.length()];
        trie.outputString(trie.root, ans, -1, outputStream);
        outputStream.flush();
    }

    static class Node {
        Node[] v = new Node[26];
        boolean isResult = false;
        int count = 0;
    }

    static class Trie {
        Node root;
        Trie() {
            root = new Node();
        }
        void mergeString(String s) {
            Node currentRoot = root;

            int idx = 0;
            int len = s.length();
            boolean hasRemoved = false;
            while (idx < len) {
                if (idx == len - 1 || s.charAt(idx + 1) == ' ') {
                    if (hasRemoved) {
                        int c = s.charAt(idx) - 'a';
                        if (currentRoot.v[c] == null) {
                            currentRoot.v[c] = new Node();
                        }
                        currentRoot = currentRoot.v[c];
                    }
                    currentRoot.isResult = true;
                    currentRoot.count += 1;
                    idx += 2;
                    hasRemoved = false;
                    currentRoot = root;
                } else {
                    if (s.charAt(idx) > s.charAt(idx+1) && !hasRemoved) {
                        // skip this char
                        hasRemoved = true;
                    } else {
                        // insert
                        int c = s.charAt(idx) - 'a';
                        if (currentRoot.v[c] == null) {
                            currentRoot.v[c] = new Node();
                        }
                        currentRoot = currentRoot.v[c];
                    }
                    idx += 1;
                }


            }

            root.count = 0;
            root.isResult = false;
        }

        void outputString(Node currentRoot, byte[] stack, int currentIdx, BufferedOutputStream outputStream) throws IOException {
            if (currentRoot.isResult) {
                // output sb
                int times = 0;
                while (times < currentRoot.count) {

                    for (int idx = 0; idx <= currentIdx; idx++) {
                        outputStream.write(stack[idx]);
                    }
                    times += 1;
                }
            }
            for (int idx = 0; idx < 26; idx++) {
                if (currentRoot.v[idx] != null) {
                    stack[++currentIdx] = (byte) ('a' + idx);
                    outputString(currentRoot.v[idx], stack, currentIdx, outputStream);
                    currentIdx--;
                }
            }
        }
    }
}