백준 11655번 ROT13 [ Java ]

11655번: ROT13

import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();

        char str[] = br.readLine().toCharArray();
        for (char ch : str) {
            if ('a' <= ch && ch <= 'z' - 13)
                sb.append((char)(ch + 13));
            else if ('z' - 13 < ch & ch <= 'z')
                sb.append((char)(ch - 13));
            else if ('A' <= ch && ch <= 'Z' - 13)
                sb.append((char)(ch + 13));
            else if ('Z' - 13 < ch && ch <= 'Z')
                sb.append((char)(ch - 13));
            else
                sb.append(ch);
        }
        System.out.print(sb);
    }
}