Word Pattern

Problem statement

Given a pattern and a string s, find if s follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in s.

Example 1:

Input: pattern = "abba", s = "dog cat cat dog"Output: true

Example 2:

Input: pattern = "abba", s = "dog cat cat fish"Output: false

Example 3:

Input: pattern = "aaaa", s = "dog cat cat dog"Output: false

Constraints:

• 1 <= pattern.length <= 300
• pattern contains only lower-case English letters.
• 1 <= s.length <= 3000
• s contains only lowercase English letters and spaces ' '.
• s does not contain any leading or trailing spaces.
• All the words in s are separated by a single space.

My solution

/**
 * @param {string} pattern
 * @param {string} s
 * @return {boolean}
 */
var wordPattern = function(pattern, s) {
    const memo = new Map();
    const seenWord = new Set();
    
    const sArr = s.split(/\W/)
    
    for (const mat of pattern) {
        const word = sArr.shift()
        
        // console.log(word) 
        
        if (word !== undefined && !memo.has(mat) && !seenWord.has(word)) {
            memo.set(mat, word)
            seenWord.add(word)
        } else if (memo.get(mat) !== word || word === undefined) {
            return false;
        }
    }
    
    console.log(memo, seenWord)
    
    if (sArr.length) {
        return false
    }
    
    return true
};