Video Time Interval Calculation

gistfile1.txt

/**
 * Title : Get Video Watch-Time from Watch Intervals
 * 
 * Given a list of Video Intervals a user has watched for a video, Find the total watch time of the Video for the User
 * 
 * for example : if the given List of Intervals are - (0,10), (20,30), (20,40), (15,30)
 * 
 * then we should get a WatchTime of 30 and actual Intervals are (0,10) and (20,40)
 * 
    Output Should be like :
  
  	VideoInterval(startTimeInMills=0, endTimeInMills=10)
	VideoInterval(startTimeInMills=20, endTimeInMills=40)
	watchTime = 30
 */
//(10,20), (30, 40), (0,20)
fun main() {
    val videoIntervals : List<VideoInterval> = listOf(VideoInterval(10,20),VideoInterval(30,40),VideoInterval(0,30))
    val newList = videoIntervals.sortedWith(compareBy<VideoInterval>{
        it.startTimeInMills
    })


   
    println(computeTotalTime(newList).toString())
 }

fun computeTotalTime(list: List<VideoInterval>) : Int {
    var totalTime = 0
    var startIndex = 0
    var endIndex = 0
    var compute = false
    list.forEach {
        compute = false
        if(totalTime == 0) {
            startIndex = it.startTimeInMills
            endIndex = it.endTimeInMills
            compute = true
        } else {
            if(it.startTimeInMills >= endIndex) {
                startIndex = it.startTimeInMills
            	endIndex = it.endTimeInMills
                compute = true
            } else if(it.endTimeInMills >= endIndex) {
                startIndex = endIndex
                endIndex = it.endTimeInMills
                compute = true
            } else {
                list.remove(this)
            }
            
            ///it.startTimeInMills >= endIndex || it.endTimeInMills >= endIndex
        }
        if(compute) {
            totalTime += endIndex - startIndex
        }  
    }
    
    return totalTime
}

data class VideoInterval(val startTimeInMills : Int, val endTimeInMills : Int)