[LeetCode]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.

public class Solution {
    public boolean isIsomorphic(String s, String t) {
        Map<Character,Character> map = new HashMap<>();
        Map<Character,Character> reMap = new HashMap<>();
        for(int i=0;i<s.length();i++){
        	char c = s.charAt(i);
        	char rc = t.charAt(i);
        	if(map.containsKey(c)){
        		if(rc!=map.get(c)) return false;
        	}else{
        		if(reMap.containsKey(rc)) return false;
        		map.put(c, rc);
        		reMap.put(rc, c);
        	}
        }
        return true;
    }
}