[JAVA 인프런 강의] 문자열 - 특정 문자열 뒤집기

public class Solution {
    public String solution(String str){
        String answer = "";
        char[] arr = str.toCharArray();
        int lp =0, rp = str.length()-1;

        while(lp<rp){
            if(!Character.isAlphabetic(arr[lp])){
                lp++;
            } else if(!Character.isAlphabetic(arr[rp])){
                rp--;
            } else { // 둘 다 알파벳
                char temp = arr[lp];
                arr[lp] = arr[rp];
                arr[rp] = temp;
                lp++;
                rp--;
            }
        }
        answer = String.valueOf(arr);
        return answer;
    }

    public static void main(String[] args) {
        Solution T = new Solution();
        System.out.println(T.solution("a#b!GE*T@s"));
    }
}