gistfile1.txt

/**
  clientDurations = [1,2,3]
  numTicketWindows = 2
  getTimeToComplete(clientDurations, numTicketWindows) // 3
 */
 
function getTimeToServeClients(clientDurations, numTicketWindows) {
    /* Array of durations clients have spent in each ticket window. */
    const cumulativeDurations = new Array(numTicketWindows).fill(0)

    clientDurations.forEach(cd => {
        /* Let the least busy window to serve the client. */
        const minDurationIdx = cumulativeDurations.indexOf(Math.min(...cumulativeDurations))
        cumulativeDurations[minDurationIdx] += cd
    })
   
    return Math.max(...cumulativeDurations)
}