A company currently pays a fixed sum for the use of a particular licensed software package.   In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.

Assume the software's licensing daemon faithfully records a checkout event when a copy of the software starts and a checkin event when the software finishes to its log file.

An example of checkout and checkin events are:

 License OUT @ 2008/10/03_23:51:05 for job 4974
 ...
 License IN  @ 2008/10/04_00:18:22 for job 4974



Task

Save the 10,000 line log file from    here   into a local file, then write a program to scan the file extracting both the maximum licenses that were out at any time, and the time(s) at which this occurs.

Mirror of log file available as a zip here (offsite mirror).




// version 1.1.51
 
import java.io.File
 
fun main(args: Array<String>) {
    val filePath = "mlijobs.txt"
    var licenses = 0
    var maxLicenses = 0
    val dates = mutableListOf<String>()
    val f = File(filePath) 
 
    f.forEachLine { line ->
        if (line.startsWith("License OUT")) {
            licenses++
            if (licenses > maxLicenses) {
                maxLicenses = licenses
                dates.clear() 
                dates.add(line.substring(14, 33))
            }
            else if(licenses == maxLicenses) {
                dates.add(line.substring(14, 33))
            }
        }
        else if (line.startsWith("License IN")) {
            licenses--
        }
    }
    println("Maximum simultaneous license use is $maxLicenses at the following time(s):")
    println(dates.map { "  $it" }.joinToString("\n"))               
}