import java.util.Arrays;

import java.util.HashMap;

public class IsIsomorphic{

public static boolean isIsomorphic(String s, String t){

if(s.length() != t.length())

return false;

if(s.length() == 0 && t.length() == 0)

return true;

HashMap<Character, Character> map = new HashMap<Character, Character>();

for(int i=0; i < s.length(); i++){

char c1 = s.charAt(i);

char c2 = t.charAt(i);

if(map.containsKey(c1)){

if(c2 != map.get(c1))

return false;

}

else

map.put(c1,c2);

}

return true;

}

public static void main(String[] args){

if(args.length < 2){

System.out.println("usage : java <program> <string1> <string2>");

}

else{

System.out.println("This program checks if two given string s and t are isomorphic.\n Two Strings are isomorphic if the characters in s can be replaced to get t");

String s = args[0];

String t = args[1];

boolean result = isIsomorphic(s,t);

if(result)

System.out.println(s + " and " + t + " are isomorphic");

else

System.out.println(s + " and " + t + " are not isomorphic");

}

}

}