[3차] 압축 (2018 KAKAO BLIND RECRUITMENT)

원본 : https://school.programmers.co.kr/learn/courses/30/lessons/17684

프로그래머스

 

풀이

import java.util.*;

class Solution {
    public int[] solution(String msg) {
        LinkedList<String> list = new LinkedList<>(Arrays.asList(msg.split("")));
        List<String> dictionary = new ArrayList<>();

        for (char ch = 'A'; ch <= 'Z'; ch++) {
            dictionary.add(String.valueOf(ch));
        }

        StringBuilder result = new StringBuilder();
        StringBuilder sb;

        while (!list.isEmpty()) {
            sb = new StringBuilder(list.poll());

            while (true) {
                if (list.isEmpty()) {
                    break;
                }

                sb.append(list.poll());

                if (!dictionary.contains(sb.toString())) {
                    break;
                }
            }

            if (list.isEmpty()) {
                if (dictionary.contains(sb.toString())) {
                    result.append(dictionary.indexOf(sb.toString()) + 1).append(",");
                } else {
                    String lastStr = String.valueOf(sb.charAt(sb.length() - 1));
                    String preStr = sb.deleteCharAt(sb.length() - 1).toString();

                    result.append(dictionary.indexOf(preStr) + 1).append(",");
                    result.append(dictionary.indexOf(lastStr) + 1).append(",");
                }
            } else {
                dictionary.add(sb.toString());

                if (sb.length() >= 2) {
                    list.addFirst(String.valueOf(sb.charAt(sb.length() - 1)));
                    sb.deleteCharAt(sb.length() - 1);
                }

                result.append(dictionary.indexOf(sb.toString()) + 1).append(",");
            }
        }

        return Arrays.stream(result.deleteCharAt(result.length() - 1).toString().split(",")).mapToInt(Integer::parseInt).toArray();
    }
}