JAVA 백준2529 부등호(BOJ2529)

문제링크 : https://www.acmicpc.net/problem/2529

2529번: 부등호

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

public class BOJ2529 {
    static StringBuilder sb = new StringBuilder(); //제출답안
    static FastReader scan = new FastReader();

    static int N;
    static double maxValue, minValue;
    static int[] isUsed, selected;
    static String[] simbols;
    static String maxString, minString;

    public static void input() {
        N = scan.nextInt();
        simbols = new String[N];
        for(int i =0; i < N; i++) {
            simbols[i] = scan.next();
        }
    }

    public static void main(String[] args) {
        input();

        maxValue = Double.MIN_VALUE;
        minValue = Double.MAX_VALUE;
        isUsed = new int[10];
        selected = new int[N+1];

        recFunc(0);

        System.out.println(maxString);
        System.out.println(minString);

    }
    //문자를 숫자로 바꿔서 비교후 원래 문자를 사용하는 부분이.. 조금 더 깔끔하게 할 수 있을것같다.
    public static void recFunc(int k) {
        if(k == N+1) {
            for(int i =0; i < N; i++) {
                if(simbols[i].equals(">")) {
                    if(!(selected[i] > selected[i+1])) {
                        //부등호 만족하지않으면 취소
                        return;
                    }
                }else if(simbols[i].equals("<")) {
                    if(!(selected[i] < selected[i+1])) {
                        //부등호 만족하지않으면 취소
                        return;
                    }
                }
            }
            //숫자를 이어붙일 문자
            String value = "";
            for(int i =0; i < N+1; i++) {
                value += String.valueOf(selected[i]);
            }
            //문자 -> 숫자 로해서 크기비교
            Double finalValue = Double.parseDouble(value);
            if(finalValue > maxValue) {
                maxValue = finalValue;
                maxString = value;
            }
            if(finalValue < minValue) {
                minValue = finalValue;
                minString = value;
            }

        } else {
            for(int i =0; i<10; i++) {
                if(isUsed[i] == 1) {
                    continue;
                }
                isUsed[i] = 1;
                selected[k] = i;
                recFunc(k+1);
                isUsed[i] = 0;
                selected[k] = 0;
            }
        }
    }
    /*
    *
    *류호석 강사님 입력 템플릿
    *
    */
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        public FastReader(String s) throws FileNotFoundException {
            br = new BufferedReader(new FileReader(new File(s)));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
}