Function carry

javascript/0066-plus-one.js:17–26

(digits)

var add = (digits) => (digits[digits.length - 1] += 1);

var carry = (digits) => {
    for (let digit = digits.length - 1; 0 < digit; digit--) {
        /* Time O(N) */
        const canCarry = digits[digit] === 10;
        if (!canCarry) break;

        digits[digit] = 0;
        digits[digit - 1] += 1;
    }
};

const addLeading = (digits) => {
    const canCarry = digits[0] === 10;