class cc{ public static String encode(String enc,int offset){ offset=offset%26; StringBuilder encoded=new StringBuilder(); for(char i : enc.toCharArray()){ if(Character.isLetter(i)){ if(Character.isUpperCase(i)){ encoded.append((char) ('A'+(i-'A'+offset)%26)); } else{ encoded.append((char) ('a'+(i-'a'+offset)%26)); } } else{ encoded.append(i); } } return encoded.toString(); } public static String decode(String enc,int offset){ return encode(enc,26-offset); } public static void main(String[] args) throws java.lang.Exception{ String msg="Anna University"; System.out.println(cc.encode(msg,3)); System.out.println(cc.decode(cc.encode(msg,3),3)); } }