[2021 KAKAO BLIND RECRUITMENT] 신규 아이디 추천 (java)

문제 링크 https://programmers.co.kr/learn/courses/30/lessons/72410

문제풀이

---

참고

https://tildacoderecorder.tistory.com/93#recentEntries

https://codechacha.com/ko/java-regex/

https://velog.io/@sa1341/Java-정규-표현식