ISOMORPHIC STRINGS

ISOMORPHIC STRINGS

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

For example,
Given "egg", "add", return true.

Given "foo", "bar", return false.

Given "paper", "title", return true.

Note:
You may assume both s and t have the same length.




import java.util.*;

public class Hello {

    public static void main(String[] args) {

        //Your Code Here

         

        HashMap<Character,Character> hs=new LinkedHashMap<Character,Character>();

         

        Scanner sc=new Scanner(System.in);

        String s1=sc.next();

        String s2=sc.next();

        if(s1==null&&s2==null)

        {

            System.out.println("YES");

            return;

        }

        int n=s1.length();

        int n1=s2.length();

        if(n!=n1)

        {

            System.out.println("NO");

            return;

        }

        for(int i=0;i<n;i++)

        {char c1=s1.charAt(i);

        char c2=s2.charAt(i);

         if(hs.containsKey(c1))

         {

             if(hs.get(c1)!=c2)

             {

                 System.out.println("NO");

                 return;

             }

         }

         else{

             if(hs.containsValue(c2))

             {

              System.out.println("NO");

              return;

             }hs.put(c1,c2);

         }}

        System.out.println("YES");

         

    }

}







For More: http://www.geeksforgeeks.org/check-if-two-given-strings-are-isomorphic-to-each-other/