[알고리즘문제풀기] 그림 확대

문제

내가 작성한 정답

class Solution {
    public String[] solution(String[] picture, int k) {
        int len = picture.length, idx = 0;
        String[] answer = new String[len*k];
        for(String s:picture){
            StringBuilder sb = new StringBuilder();
            for(char c:s.toCharArray()){
                for(int i=0;i<k;i++){
                    sb.append(c);
                }
            }
            for(int j=0;j<k;j++){
                answer[idx++] = sb.toString();
            }
        }
        return answer;
    }
}

다른 사람들의 정답

class Solution {
    public String[] solution(String[] picture, int k) {
        String[] answer = new String[picture.length * k];
        int idx = 0;

        for(int i=0; i<picture.length; i++) {
            for(int j=0; j<k; j++) {
                StringBuilder sb = new StringBuilder();

                for(int l=0; l<picture[i].length(); l++) {
                    sb.append(String.valueOf(picture[i].charAt(l)).repeat(k));
                }

                answer[idx++] = sb.toString();
            }
        }

        return answer;
    }
}

import java.util.ArrayList;
import java.util.List;
class Solution {
    public String[] solution(String[] picture, int k) {
        String x = "";
        String y = "";          
        for (int i=0; i<k;i++) {
            x += ".";
            y += "x";
        }
        List<String> list = new ArrayList<>();
        for (int i=0; i<picture.length;i++) {
            for (int j=0;j<k;j++){              
                list.add(picture[i].replaceAll("[.]", x).replaceAll("[x]", y));
            }
        }
        return list.stream().toArray(String[]::new);
    }
}