[백준][15665번] N과 M (11)

문제 URL

https://www.acmicpc.net/problem/15665

나의 풀이

package backjoon;

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

public class Main {
    static int[] ans = new int[10];
    static int[] num = new int[10];
    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    public static void main(String[] args) throws IOException {
        StringTokenizer str = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(str.nextToken());
        int m = Integer.parseInt(str.nextToken());

        StringTokenizer str2 = new StringTokenizer(br.readLine());
        int[] temp = new int[n];
        for (int i = 0; i < n; i++) {
            temp[i] = Integer.parseInt(str2.nextToken());
        }
        Arrays.sort(temp);

        int j = 1;
        num[0] = temp[0];
        for (int i = 1; i < n; i++) {
            if (num[j - 1] != temp[i]) {
                num[j] = temp[i];
                j++;
            }
        }
        go(0, j, m);
        bw.flush();
        bw.close();
    }

    public static void go(int idx, int n, int m) throws IOException {
        if (idx == m) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < m; i++) {
                sb.append(num[ans[i]] + " ");
            }
            bw.write(sb.toString());
            bw.newLine();
            return;
        }

        for (int i = 0; i < n; i++) {
            ans[idx] = i;
            go(idx + 1, n, m);
        }
    }
}

첫번째 다른풀이

import java.util.*;
public class Main {
    static boolean[] c = new boolean[10];
    static int[] a = new int[10];
    static int[] num = new int[10];
    static StringBuilder go(int index, int n, int m) {
        if (index == m) {
            StringBuilder sb = new StringBuilder();
            for (int i=0; i<m; i++) {
                sb.append(num[a[i]]);
                if (i != m-1) sb.append(" ");
            }
            sb.append("\n");
            return sb;
        }
        StringBuilder ans = new StringBuilder();
        for (int i=0; i<n; i++) {
            //if (c[i]) continue;
            c[i] = true;
            a[index] = i;
            ans.append(go(index+1, n, m));
            c[i] = false;
        }
        return ans;
    }   
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int[] temp = new int[n];
        for (int i=0; i<n; i++) {
            temp[i] = sc.nextInt();
        }
        Arrays.sort(temp);
        int k = 0;
        for (int i=0; i<n; i++) {
            if (i > 0 && temp[i] == temp[i-1]) continue;
            num[k++] = temp[i];
        }
        n = k;
        System.out.print(go(0,n,m));
    }
}

두번째 다른풀이

import java.util.*;
class Result implements Comparable<Result> {
    Integer[] a;
    Result(ArrayList<Integer> a) {
        this.a = a.toArray(new Integer[a.size()]);
    }
    int get(int index) {
        return (int)this.a[index];
    }
    @Override
    public boolean equals(Object obj) {
        if (obj instanceof Result) {
            Result that = (Result)obj;
            int n = this.a.length;
            for (int i=0; i<n; i++) {
                if (this.a[i] != that.a[i]) {
                    return false;
                }
            }
            return true;
        } else {
            return false;
        }
    }
    public int compareTo(Result that) {
        int n = this.a.length;
        for (int i=0; i<n; i++) {
            if (this.a[i] == that.a[i]) continue;
            if (this.a[i] < that.a[i]) return -1;
            if (this.a[i] > that.a[i]) return 1;
        }
        return 0;
    }
}
public class Main {
    static boolean[] c = new boolean[10];
    static int[] a = new int[10];
    static int[] num = new int[10];
    static ArrayList<Result> d = new ArrayList<>();
    static void go(int index, int start, int n, int m) {
        if (index == m) {
            ArrayList<Integer> temp = new ArrayList<>();
            for (int i=0; i<m; i++) {
                temp.add(num[a[i]]);
            }
            d.add(new Result(temp));
            return;
        }
        for (int i=start; i<n; i++) {
            //if (c[i]) continue;
            c[i] = true;
            a[index] = i;
            go(index+1, 0, n, m);
            c[i] = false;
        }
    }   
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        for (int i=0; i<n; i++) {
            num[i] = sc.nextInt();
        }
        Arrays.sort(num, 0, n);
        go(0, 0, n, m);
        Collections.sort(d);
        StringBuilder sb = new StringBuilder();
        for (int i=0; i<d.size(); i++) {
            if (i == 0 || !d.get(i).equals(d.get(i-1))) {
                for (int j=0; j<m; j++) {
                    sb.append(d.get(i).get(j));
                    if (j != m-1) sb.append(' ');
                }
                sb.append('\n');
            }
        }
        System.out.print(sb);
    }
}