Function getFrequencyMaps

javascript/0567-permutation-in-string.js:35–43

(s1)

};

const getFrequencyMaps = (s1) => {
    const [s1FrequencyMap, s2FrequencyMap] = new Array(2)
        .fill()
        .map(() => new Array(26).fill(0));

    for (const char of s1) s1FrequencyMap[getCode(char)]++;

    return [s1FrequencyMap, s2FrequencyMap];
};

const getCode = (char) => char.charCodeAt(0) - 'a'.charCodeAt(0);