String (205.Isomorphic Strings)

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

The strings is isomorphic if the characters in s can is replaced to get t.

All occurrences of a character must is replaced with another character while preserving the order of characters. No, characters may map to the same character and a character may map to itself.

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

Given "foo" , "bar" return FALSE.

Given "paper" , "title" return True.

public static Boolean isisomorphic (string s, String t) {      if (s==null && t==null)  return true;      else if (s.length ()!=t.length ())  return false;      Map<character,character> hm=new hashmap<character,character> ();      for (int i=0;i<s.length (); i++) {      if (Hm.containskey (S.charat (i))) {      if (Hm.get (S.charat (i))!=t.charat (i))      return false;      }      else if (Hm.containsvalue (T.charat (i)))      return false;   Forget this condition at the beginning, pay attention to the      else      hm.put (S.charat (i), T.charat (i));      }      return true;    }

　　

String (205.Isomorphic Strings)