[Programmers] Lv.0 / 암호 해독 / Java

문제

 

풀이

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(i -> (i + 1) % code == 0)
            .mapToObj(cipher::charAt) // 문자 추출
            .map(String::valueOf) // 문자 -> 문자열
            .collect(Collectors.joining()); // 문자열 결합
    }
}

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;
    }
}

 

출처

https://school.programmers.co.kr/learn/courses/30/lessons/120892