solution.js

/**
 * @param {number[]} seats
 * @return {number}
 */
var maxDistToClosest = function(seats) {
    let start = end = maxDistance = 0,
        length = seats.length
    
    seats.forEach((seat, i) => {
        if (seat === 1) {
            if (start === 0 || end === length - 1) {
                maxDistance = Math.max(maxDistance, end - start + 1)
            } else {
                maxDistance = Math.max(maxDistance, parseInt((end - start + 1) / 2) + (end - start + 1) % 2)
            }
            if (i + 1 < length) {
                start = end = i + 1
            }
        } else {
            end = i
        }
    })
    
    if (start === 0 || end === length - 1) {
        maxDistance = Math.max(maxDistance, end - start + 1)
    } else {
        maxDistance = Math.max(maxDistance, parseInt((end - start + 1) / 2) + (end - start + 1) % 2)
    }
    
    return maxDistance
};