Function binarySearch

javascript/0300-longest-increasing-subsequence.js:104–123

(num, subsequence)

};

const binarySearch = (num, subsequence) => {
    let [left, right] = [0, subsequence.length - 1];

    while (left < right) {
        /* Time O(log(N)) */
        const mid = (left + right) >> 1;
        const guess = subsequence[mid];

        const isNumTarget = num === guess;
        if (isNumTarget) return mid;

        const isNumGreater = guess < num;
        if (isNumGreater) left = mid + 1;

        const isNumLess = num < guess;
        if (isNumLess) right = mid;
    }

    return left;
};