Function decode

javascript/0091-decode-ways.js:67–75

(s, tabu)

};

var decode = (s, tabu) => {
    for (let curr = 2; curr < tabu.length; curr++) {
        const [prev, prevPrev] = [curr - 1, curr - 2];
        const isEqual = s[prev] === '0';
        if (!isEqual) tabu[curr] += tabu[prev];

        if (isTwoDigit(s, curr)) tabu[curr] += tabu[prevPrev];
    }
};

var isTwoDigit = (s, index) => {
    const twoDigit = Number(s.slice(index - 2, index));