code: private static char decodeChar(char c, int offset) {
  		int position = (table.indexOf(c) - offset) % 52;
  		if (position < 0) {
  			position += 52;
  		}
  		return table.charAt(position);
  	}
docs: 解密轮盘
  
  @param c 字符
  @return 解密后的字符