[프로그래머스 코딩테스트]java Lv.0 문자열 겹쳐쓰기

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