gistfile1.txt

class Solution {
    public boolean isIsomorphic(String s, String t) {
        
        if (s.length() != t.length()) {
            return false;
        }

        Map<Character, Character> aMap = new HashMap<Character, Character>();
        Map<Character, Character> bMap = new HashMap<Character, Character>();
        
        for (int i = 0 ; i < s.length() ; i++) {
            
            if (!aMap.containsKey(s.charAt(i))) {
                aMap.put(s.charAt(i), t.charAt(i));
                bMap.put(t.charAt(i), s.charAt(i));
            }            
        }

        if (aMap.size() != bMap.size()) {
            return false;
        }
        
        for (int i = 0 ; i < s.length() ; i++) {

            if (aMap.get(s.charAt(i)) != t.charAt(i)) {
                    return false;
             }
        
        }
        
        return true;        
    }
}