Daily question -890 Find and replace mode

subject ：

You have a list of words  words  And a pattern   pattern, Do you want to know words Which words in match the pattern .

If there is an arrangement of letters p , Make every letter in the pattern x Replace with p(x) after , We get the words we need , So the words match the patterns .

（ Think about it , The arrangement of letters is from letter to letter ： Each letter maps to another letter , No two letters map to the same letter .）

return words List of words matching the given pattern in .

You can return the answers in any order .

Example ：

Input ：words = [“abc”,“deq”,“mee”,“aqq”,“dkd”,“ccc”], pattern = “abb”
Output ：[“mee”,“aqq”]
explain ：
“mee” Match pattern , Because there are permutations {a -> m, b -> e, …}.
“ccc” Does not match pattern , because {a -> c, b -> c, …} It's not a permutation .
because a and b Map to the same letter .

Tips ：

1 <= words.length <= 50
1 <= pattern.length = words[i].length <= 20

java Code ：

class Solution {
    public List<String> findAndReplacePattern(String[] words, String pattern) {
        List<String> ans = new ArrayList<String>();
        for (String word : words) {
            if (match(word, pattern) && match(pattern, word)) {
                ans.add(word);
            }
        }
        return ans;
    }

    public boolean match(String word, String pattern) {
        Map<Character, Character> map = new HashMap<Character, Character>();
        for (int i = 0; i < word.length(); ++i) {
            char x = word.charAt(i), y = pattern.charAt(i);
            if (!map.containsKey(x)) {
                map.put(x, y);
            } else if (map.get(x) != y) { // word  The same letter in must be mapped to  pattern  On the same letter in 
                return false;
            }
        }
        return true;
    }
}