[알고리즘문제풀기] 문자열 겹쳐쓰기

문제

내가 작성한 정답

class Solution {
    public String solution(String my_string, String overwrite_string, int s) {
        int l = overwrite_string.length(),len = my_string.length();
        String answer = my_string.substring(0,s)+overwrite_string;
        return s+l>len? answer: answer+my_string.substring(l+s);
    }
}

다른 사람들의 정답

class Solution {
    public String solution(String my_string, String overwrite_string, int s) {
        String before = my_string.substring(0, s);
        String after = my_string.substring(s + overwrite_string.length());
        return before + overwrite_string + after;
    }
}

class Solution {
    public String solution(String my_string, String overwrite_string, int s) {
        char[] my_chars = my_string.toCharArray();
        char[] overwrite_chars = overwrite_string.toCharArray();
        for (int i=0; i<overwrite_chars.length; i++) {
            my_chars[s + i] = overwrite_chars[i];
        }
        return String.valueOf(my_chars);
    }
}