(DFS기본틀) [Java] 백준 15654번 - N과 M (5)

문제 링크 : https://www.acmicpc.net/problem/15654

 

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

public class P15654 {
    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    static int N;
    static int M;
    static boolean[] visited;
    static int[] result;
    static int[] array;

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        StringTokenizer st = new StringTokenizer(br.readLine());
        N = Integer.parseInt(st.nextToken());
        M = Integer.parseInt(st.nextToken());
        visited = new boolean[N];
        result = new int[M];

        array = Arrays.stream(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
        // 사전순으로 출력해야 하기때문에 정렬
        Arrays.sort(array);
        dfs(0);


        bw.flush();
        bw.close();
        br.close();
    }

    public static void dfs(int depth) throws IOException {
        if (depth == M) {
            StringBuilder sb = new StringBuilder();
            for (int i : result) {
                sb.append(i).append(" ");
            }
            bw.append(sb).append("\n");
            return;
        }

        for (int i = 0; i < N; i++) {
        // 중복조합이 아니라 visited 사용
            if (!visited[i]) {
                visited[i] = true;
                result[depth] = array[i];
                dfs(depth + 1);
                visited[i] = false;
            }
        }
    }
}