[완전탐색] 백준 2529 부등호 JAVA

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class ES_11_2529 {
    static String[] sign;
    static int k;
    static List<String> matchSignList = new ArrayList<>(); // 완성된 애들 넣어놓기
    static boolean[] visited = new boolean[10];

    // [완전탐색] 백준 2529 부등호 JAVA
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        k = Integer.parseInt(br.readLine());
        sign = br.readLine().split(" ");

        for (int i = 0 ; i < 10 ; i++) {
            if (!visited[i]) {
                dfs(i, 0, i+"");
            }
            visited = new boolean[10];
        }
        System.out.println(matchSignList.get(matchSignList.size()-1));
        System.out.println(matchSignList.get(0));
    }

    private static void dfs(int num, int signIdx, String finalNumStr) {
        if (finalNumStr.length() == k+1) {
            matchSignList.add(finalNumStr);
            return;
        }
        visited[num] = true;
        String nowSign = sign[signIdx];
        for (int i = 0 ; i < 10 ; i++) {
            if (!visited[i]) {
                if ((nowSign.equals(">") && num > i) || (nowSign.equals("<") && num < i)){
                    dfs(i, signIdx+1, finalNumStr+i);
                }
            }
        }
        visited[num] = false;
    }
}