백준 1259번 펠린트롬수 [ Java ]

1259번: 팰린드롬수

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

public class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        while (true){
            char[] str = br.readLine().toCharArray();
            boolean flag = true;
            if (str[0]=='0') {
                System.out.print(sb);
                System.exit(0);
            }
            for (int i=0;i<str.length/2; i++)
                if (str[i] != str[str.length-1-i])
                    flag = false;
            sb.append(flag ? "yes\n" : "no\n");
        }
    }
}