인프런 커뮤니티 질문&답변

import java.io.*;
import java.util.*;

class Solution {
	public static String solution(String str) {
		char[] s = str.toCharArray();
		int lt = 0, rt = str.length() - 1;
		while(lt < rt) {
			if(!Character.isAlphabetic(s[lt]))
				lt++;
			else if(!Character.isAlphabetic(s[rt]))
				rt--;
			else {
				char tmp = s[lt];
				s[lt] = s[rt];
				s[rt] = tmp;
				lt++;
				rt--;
			}
		}
		return String.valueOf(s);
	}
	
    public static void main(String[] args) throws IOException {
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    	String str = br.readLine();
    	System.out.println(solution(str));
    }
}