백준 1759

package baekjoon.브루트포스.백트래킹;

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

public class Main1759 {

   static int L, C;
   static char[] chars;
   static int[] selected;
   static StringBuilder sb = new StringBuilder();

   static void go(int k) {
      if (k == L + 1) {
         int vowel = 0, consonant = 0;
         for (int i = 1; i <= L; i++) {
            if (isVowel(chars[selected[i]])) {
               vowel++;
            } else {
               consonant++;
            }
         }
         if (vowel >= 1 && consonant >= 2) {
            for (int i = 1; i <= L; i++) {
               sb.append(chars[selected[i]]);
            }
            sb.append("\n");
         }
      } else {
         for (int i = selected[k - 1] + 1; i <= C; i++) {
            selected[k] = i;
            go(k + 1);
            selected[k] = 0;
         }

      }
   }

   private static boolean isVowel(char x) {
      return x == 'a' || x == 'e' || x == 'i' || x == 'o' || x == 'u';
   }

   public static void main(String[] args) throws Exception {
      input();
      Arrays.sort(chars, 1, C + 1);
      go(1);
      System.out.println(sb);
   }

   private static void input() throws IOException {
      BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      StringTokenizer st = new StringTokenizer(br.readLine());
      L = Integer.parseInt(st.nextToken());
      C = Integer.parseInt(st.nextToken());
      chars = new char[C + 1];
      selected = new int[L + 1];
      st = new StringTokenizer(br.readLine());
      for (int i = 1; i <= C; i++) {
         chars[i] = st.nextToken().charAt(0);
      }
   }

}