findAndReplacePattern.js created by smakar20 - https://repl.it/@smakar20/findAndReplacePatternjs

index.js

/*
You have a list of words and a pattern, and you want to know which words in words matches the pattern.

A word matches the pattern if there exists a permutation of letters p so that after replacing every letter x in the pattern with p(x), we get the desired word.

(Recall that a permutation of letters is a bijection from letters to letters: every letter maps to another letter, and no two letters map to the same letter.)

Return a list of the words in words that match the given pattern. 

You may return the answer in any order.

 

Example 1:

Input: words = ["abc","deq","mee","aqq","dkd","ccc"], pattern = "abb"
Output: ["mee","aqq"]
Explanation: "mee" matches the pattern because there is a permutation {a -> m, b -> e, ...}. 
"ccc" does not match the pattern because {a -> c, b -> c, ...} is not a permutation,
since a and b map to the same letter.
 

Note:

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

var findAndReplacePattern = function(words, pattern) {
    var output = [];
    var patternSetSize = (new Set(pattern.split(''))).size;
    for (var word of words){
        if ((word.length !== pattern.length) || ((new Set(word.split(''))).size !== patternSetSize)) continue;
        var wordObj = {};
        var count = 0;
        for (var i = 0; i < word.length; i++){
          if(wordObj[word[i]] !== undefined && wordObj[word[i]] !== pattern[i]) break;
          
           wordObj[word[i]] = pattern[i];
            count++;
        }
        if (count === pattern.length) output.push(word);
    }
    return output;
};

findAndReplacePattern(["abc","deq","mee","aqq","dkd","ccc", "inn"], "abb");
// Output: ["mee","aqq", "inn"]