프로그래머스 레벨1) 신규 아이디 추천

class Solution {
    public String solution(String new_id) {
        String word = new_id;
        String result = "";

        //1
        word = word.toLowerCase();
        //2
        word = word.replaceAll("\\~|\\!|\\@|\\#|\\$|\\%|\\^|\\&|\\*|\\(|\\)|\\=|\\+|\\[|\\{|\\]|\\}|\\:|\\?|\\,|\\<|\\>|\\/", "");
        //3
        word = word.replaceAll("\\.+", ".");
        //4
        word = word.replaceAll("^\\.", "");
        word = word.replaceAll("\\.$", "");
        //5
        if(word.length()==0) word="a";
        //6
        if(word.length()>15) {
            word = word.substring(0, 15);
            word = word.replaceAll("\\.$", "");
        }
        //7
        if(word.length()<=2) {
            String dup = word.substring(word.length()-1, word.length());
            result = word;
            for(int i=word.length(); i<3; i++) {
                result += dup;
            }
        } else {
            result = word;
        }
        return result;
    }

}

 

* 정규식, charAt()의 사용

class Solution {
    public String solution(String new_id) {
        String answer = "";
        String temp = new_id.toLowerCase();

        temp = temp.replaceAll("[^-_.a-z0-9]","");
        System.out.println(temp);
        temp = temp.replaceAll("[.]{2,}",".");
        temp = temp.replaceAll("^[.]|[.]$","");
        System.out.println(temp.length());
        if(temp.equals(""))
            temp+="a";
        if(temp.length() >=16){
            temp = temp.substring(0,15);
            temp=temp.replaceAll("^[.]|[.]$","");
        }
        if(temp.length()<=2)
            while(temp.length()<3)
                temp+=temp.charAt(temp.length()-1);

        answer=temp;
        return answer;
    }
}

 

* 정규식, 객체지향적인, Method Chain, charAt()의 사용

 

lass Solution {
    public String solution(String new_id) {

        String s = new KAKAOID(new_id)
                .replaceToLowerCase()
                .filter()
                .toSingleDot()
                .noStartEndDot()
                .noBlank()
                .noGreaterThan16()
                .noLessThan2()
                .getResult();

        return s;
    }

    private static class KAKAOID {
        private String s;

        KAKAOID(String s) {
            this.s = s;
        }

        private KAKAOID replaceToLowerCase() {
            s = s.toLowerCase();
            return this;
        }

        private KAKAOID filter() {
            s = s.replaceAll("[^a-z0-9._-]", "");
            return this;
        }

        private KAKAOID toSingleDot() {
            s = s.replaceAll("[.]{2,}", ".");
            return this;
        }

        private KAKAOID noStartEndDot() {
            s = s.replaceAll("^[.]|[.]$", "");
            return this;
        }

        private KAKAOID noBlank() {
            s = s.isEmpty() ? "a" : s;
            return this;
        }

        private KAKAOID noGreaterThan16() {
            if (s.length() >= 16) {
                s = s.substring(0, 15);
            }
            s = s.replaceAll("[.]$", "");
            return this;
        }

        private KAKAOID noLessThan2() {
            StringBuilder sBuilder = new StringBuilder(s);
            while (sBuilder.length() <= 2) {
                sBuilder.append(sBuilder.charAt(sBuilder.length() - 1));
            }
            s = sBuilder.toString();
            return this;
        }

        private String getResult() {
            return s;
        }
    }
}