[알고리즘문제풀기] 9로 나눈 나머지

문제

내가 작성한 정답

char

class Solution {
    public int solution(String number) {
        int answer = 0;
        for(char c : number.toCharArray()){
            answer += c-'0';
        }
            return answer%9;
    }
}

// stream
import java.util.Arrays;

class Solution {
    public int solution(String number) {
        return number.chars()
                .map(c->c-'0')
                .sum()%9;
    }
}

String

class Solution {
    public int solution(String number) {
        int answer = 0;
        for(String s : number.split("")){
            answer += Integer.parseInt(s);
        }
        return answer%9;
    }
}

// stream
import java.util.Arrays;

class Solution {
    public int solution(String number) {
        return Arrays.stream(number.split(""))
                .mapToInt(s-> Integer.parseInt(s))
                .sum()%9;

    }
}