[白俊]2529号不等式-Java,Java

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コード#コード#

package 백트래킹;

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

public class BO2529 {
    static int k; // 부등호문자의 개수(2<=k<=9)
    static boolean[] visit = new boolean[10]; //0-9 숫자 방문여부(중복숫자불가하므로)
    static char[] signs;
    static ArrayList<String> list = new ArrayList<>();

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        k = Integer.parseInt(br.readLine());

        signs = new char[k];
        StringTokenizer st = new StringTokenizer(br.readLine());
        for (int i = 0; i < k; i++) {
            signs[i] = st.nextToken().charAt(0);
        }
        back("", 0);

        System.out.println(list.get(list.size() - 1));
        System.out.println(list.get(0));
    }

    static void back(String num, int depth) {
        if (depth == k + 1) {
//            min = Math.min(Integer.parseInt(num), min);
//            max = Math.max(Integer.parseInt(num), min); 021->21로출력
            list.add(num);
            return;
        }

        for (int i = 0; i <= 9; i++) {
            if (depth == 0 || !visit[i] && compare(num.charAt(num.length() - 1) - '0', i, signs[depth - 1])) {
                //처음건 비교할게없으므로 통과 || 방문안한숫자 && 비교
                visit[i] = true;
                back(num + i, depth + 1);
                visit[i] = false;
            }
        }
    }


    static boolean compare(int a, int b, int c) {
        if (c == '<') return a < b;
        else return a > b;
    }
}