Refactor assignment 3 and implement alternative Pareto Principle

src/assignment/week3/taxipark/TaxiParkTask.kt

@@ -1,4 +1,4 @@
-package taxipark
+package assignment.week3.taxipark
 
 /*
  * Task #1. Find all the drivers who performed no trips.
@@ -49,13 +49,13 @@ fun TaxiPark.findSmartPassengers(): Set<Passenger> = this.allPassengers
  * Return any period if many are the most frequent, return `null` if there're no trips.
  */
 fun TaxiPark.findTheMostFrequentTripDurationPeriod(): IntRange? {
-    val maxDuration = this.trips
+    val (maxDuration, _) = this.trips
         .map { trip -> trip.duration / 10 }
         .groupBy { it }
-        .maxByOrNull { it.value.size }
+        .maxByOrNull { it.value.size } ?: return null
 
-    val startRange = maxDuration?.let { it.key * 10 }
-    return startRange?.let { it.rangeTo(it + 9) }
+    val startRange = maxDuration * 10
+    return startRange.rangeTo(startRange + 9)
 }
 
 /*