Leetcode 205:isomorphic Strings

Given strings sand T, determine if they is isomorphic.

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

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.

Note:
Assume both s and T have the same length.

Ideas

Create a map to save the mapping relationship, while maintaining the mapped char with a set, ensuring that the same char is not mapped two times.

[CODE]

public class Solution {    //test case: ' Egg ', ' Add ' public        Boolean isisomorphic (string s, String t) {        //init che CK        if (s==null | | t==null) return false;        if (s.length () = T.length ()) return false;                Map<character, character> map = new Hashmap<character, character> ();        set<character> set = new Hashset<character> ();                for (int i=0; i<s.length (); i++) {            char C1 = S.charat (i);            char C2 = T.charat (i);                        if (Map.containskey (C1)) {                if (Map.get (c1)! = C2) return false;            } else {                if (set.contains (C2)) return False ;                else {                    map.put (c1, C2);                    Set.add (C2);        }}} return true;    }}

Leetcode 205:isomorphic Strings