[알고리즘문제풀기] 암호 해독

문제

내가 작성한 정답

class Solution {
    public String solution(String cipher, int code) {
        StringBuilder answer = new StringBuilder(); 
        for(int i=code-1; i<cipher.length(); i+=code ){
            answer.append(cipher.charAt(i));
        }
        return answer.toString();
    }
}

다른 사람들의 정답

class Solution {
    public String solution(String cipher, int code) {
        String answer = "";

        for (int i = code; i <= cipher.length(); i = i + code) {
            answer += cipher.substring(i - 1, i);
        }

        return answer;
    }
}

import java.util.stream.Collectors;
import java.util.stream.IntStream;

class Solution {
    public String solution(String cipher, int code) {
        return IntStream.range(0, cipher.length())
                .filter(value -> value % code == code - 1)
                .mapToObj(c -> String.valueOf(cipher.charAt(c)))
                .collect(Collectors.joining());
    }
}